From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 402B1C33CB1 for ; Wed, 15 Jan 2020 14:49:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 07502214AF for ; Wed, 15 Jan 2020 14:49:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729061AbgAOOtt (ORCPT ); Wed, 15 Jan 2020 09:49:49 -0500 Received: from mga18.intel.com ([134.134.136.126]:13904 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729058AbgAOOtt (ORCPT ); Wed, 15 Jan 2020 09:49:49 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jan 2020 06:49:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,322,1574150400"; d="scan'208";a="253818572" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by fmsmga001.fm.intel.com with SMTP; 15 Jan 2020 06:49:39 -0800 Received: by stinkbox (sSMTP sendmail emulation); Wed, 15 Jan 2020 16:49:38 +0200 Date: Wed, 15 Jan 2020 16:49:38 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Thomas Zimmermann Cc: airlied@linux.ie, daniel@ffwll.ch, alexander.deucher@amd.com, christian.koenig@amd.com, David1.Zhou@amd.com, maarten.lankhorst@linux.intel.com, patrik.r.jakobsson@gmail.com, robdclark@gmail.com, sean@poorly.run, benjamin.gaignard@linaro.org, vincent.abriou@st.com, yannick.fertre@st.com, philippe.cornu@st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, eric@anholt.net, rodrigosiqueiramelo@gmail.com, hamohammed.sa@gmail.com, linux-graphics-maintainer@vmware.com, thellstrom@vmware.com, bskeggs@redhat.com, harry.wentland@amd.com, sunpeng.li@amd.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, freedreno@lists.freedesktop.org Subject: Re: [Intel-gfx] [PATCH v2 03/21] drm: Add get_vblank_timestamp() to struct drm_crtc_funcs Message-ID: <20200115144938.GA13686@intel.com> References: <20200115121652.7050-1-tzimmermann@suse.de> <20200115121652.7050-4-tzimmermann@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200115121652.7050-4-tzimmermann@suse.de> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org On Wed, Jan 15, 2020 at 01:16:34PM +0100, Thomas Zimmermann wrote: > The callback get_vblank_timestamp() is currently located in struct > drm_driver, but really belongs into struct drm_crtc_funcs. Add an > equivalent there. Driver will be converted in separate patches. > > The default implementation is drm_calc_vbltimestamp_from_scanoutpos(). > The patch adds drm_crtc_vblank_helper_get_vblank_timestamp(), which is > an implementation for the CRTC callback. > > v2: > * rename helper to drm_crtc_vblank_helper_get_vblank_timestamp() > * replace drm_calc_vbltimestamp_from_scanoutpos() with > drm_crtc_vblank_helper_get_vblank_timestamp() in docs > > Signed-off-by: Thomas Zimmermann > --- > drivers/gpu/drm/drm_vblank.c | 236 +++++++++++++++++++++-- > include/drm/drm_crtc.h | 46 ++++- > include/drm/drm_modeset_helper_vtables.h | 4 +- > include/drm/drm_vblank.h | 26 ++- > 4 files changed, 292 insertions(+), 20 deletions(-) > > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index abb085c67d82..1b7af316e6a5 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -333,7 +333,9 @@ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc) > u64 vblank; > unsigned long flags; > > - WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !dev->driver->get_vblank_timestamp, > + WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && > + !crtc->funcs->get_vblank_timestamp && > + !dev->driver->get_vblank_timestamp, > "This function requires support for accurate vblank timestamps."); > > spin_lock_irqsave(&dev->vblank_time_lock, flags); > @@ -511,9 +513,9 @@ EXPORT_SYMBOL(drm_crtc_vblank_waitqueue); > * > * Calculate and store various constants which are later needed by vblank and > * swap-completion timestamping, e.g, by > - * drm_calc_vbltimestamp_from_scanoutpos(). They are derived from CRTC's true > - * scanout timing, so they take things like panel scaling or other adjustments > - * into account. > + * drm_crtc_vblank_helper_get_vblank_timestamp(). They are derived from > + * CRTC's true scanout timing, so they take things like panel scaling or > + * other adjustments into account. > */ > void drm_calc_timestamping_constants(struct drm_crtc *crtc, > const struct drm_display_mode *mode) > @@ -577,8 +579,9 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants); > * > * Implements calculation of exact vblank timestamps from given drm_display_mode > * timings and current video scanout position of a CRTC. This can be directly > - * used as the &drm_driver.get_vblank_timestamp implementation of a kms driver > - * if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position or > + * &drm_driver.get_scanout_position is implemented. > * > * The current implementation only handles standard video modes. For double scan > * and interlaced modes the driver is supposed to adjust the hardware mode > @@ -742,15 +745,22 @@ static bool > drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, > ktime_t *tvblank, bool in_vblank_irq) > { > + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); > bool ret = false; > > /* Define requested maximum error on timestamps (nanoseconds). */ > int max_error = (int) drm_timestamp_precision * 1000; > > /* Query driver if possible and precision timestamping enabled. */ > - if (dev->driver->get_vblank_timestamp && (max_error > 0)) > + if (crtc->funcs->get_vblank_timestamp && (max_error > 0)) { Could drop the superfluous parens while at it. Are all drivers utilizing this guaranteed to have the crtc here? > + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); > + > + ret = crtc->funcs->get_vblank_timestamp(crtc, &max_error, > + tvblank, in_vblank_irq); > + } else if (dev->driver->get_vblank_timestamp && (max_error > 0)) { > ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error, > tvblank, in_vblank_irq); > + } > > /* GPU high precision timestamp query unsupported or failed. > * Return current monotonic/gettimeofday timestamp as best estimate. > @@ -1059,11 +1069,19 @@ EXPORT_SYMBOL(drm_crtc_vblank_get); > > static bool __vblank_disable_immediate(struct drm_device *dev, unsigned int pipe) > { > + struct drm_crtc *crtc; > + > if (!dev->vblank_disable_immediate) > return false; > - if (!dev->driver->get_vblank_timestamp) > - return false; > - return true; > + > + crtc = drm_crtc_from_index(dev, pipe); > + if (crtc && crtc->funcs->get_vblank_timestamp) Here you are expecting that the crtc might be NULL. > + return true; > + > + if (dev->driver->get_vblank_timestamp) > + return true; > + > + return false; > } > > static void drm_vblank_put(struct drm_device *dev, unsigned int pipe) > @@ -1742,9 +1760,11 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data, > > static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe) > { > + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); > struct drm_pending_vblank_event *e, *t; > ktime_t now; > u64 seq; > + bool high_prec; > > assert_spin_locked(&dev->event_lock); > > @@ -1764,8 +1784,10 @@ static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe) > send_vblank_event(dev, e, seq, now); > } > > - trace_drm_vblank_event(pipe, seq, now, > - dev->driver->get_vblank_timestamp != NULL); > + high_prec = crtc->funcs->get_vblank_timestamp || > + dev->driver->get_vblank_timestamp; Here again assuming the crtc can't be NULL. > + > + trace_drm_vblank_event(pipe, seq, now, high_prec); > } > > /** > @@ -2020,3 +2042,193 @@ int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data, > kfree(e); > return ret; > } > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp_internal - precise vblank > + * timestamp helper > + * @dev: DRM device > + * @pipe: index of CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * @get_scanout_position: > + * Callback function to retrieve the scanout position. See > + * @struct drm_crtc_helper_funcs.get_scanout_position. > + * > + * Implements calculation of exact vblank timestamps from given drm_display_mode > + * timings and current video scanout position of a CRTC. > + * > + * The current implementation only handles standard video modes. For double scan > + * and interlaced modes the driver is supposed to adjust the hardware mode > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers) to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode)) > +{ > + struct drm_device *dev = crtc->dev; > + unsigned int pipe = crtc->index; > + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; > + struct timespec64 ts_etime, ts_vblank_time; > + ktime_t stime, etime; > + bool vbl_status; > + const struct drm_display_mode *mode; > + int vpos, hpos, i; > + int delta_ns, duration_ns; > + > + if (pipe >= dev->num_crtcs) { > + DRM_ERROR("Invalid crtc %u\n", pipe); > + return false; > + } > + > + /* Scanout position query not supported? Should not happen. */ > + if (!get_scanout_position) { > + DRM_ERROR("Called from CRTC w/o get_scanout_position()!?\n"); > + return false; > + } > + > + if (drm_drv_uses_atomic_modeset(dev)) > + mode = &vblank->hwmode; > + else > + mode = &crtc->hwmode; > + > + /* If mode timing undefined, just return as no-op: > + * Happens during initial modesetting of a crtc. > + */ > + if (mode->crtc_clock == 0) { > + DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe); > + WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev)); > + return false; > + } > + > + /* Get current scanout position with system timestamp. > + * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times > + * if single query takes longer than max_error nanoseconds. > + * > + * This guarantees a tight bound on maximum error if > + * code gets preempted or delayed for some reason. > + */ > + for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { > + /* > + * Get vertical and horizontal scanout position vpos, hpos, > + * and bounding timestamps stime, etime, pre/post query. > + */ > + vbl_status = get_scanout_position(crtc, in_vblank_irq, &vpos, > + &hpos, &stime, &etime, mode); > + > + /* Return as no-op if scanout query unsupported or failed. */ > + if (!vbl_status) { > + DRM_DEBUG("crtc %u : scanoutpos query failed.\n", > + pipe); > + return false; > + } > + > + /* Compute uncertainty in timestamp of scanout position query. */ > + duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime); > + > + /* Accept result with < max_error nsecs timing uncertainty. */ > + if (duration_ns <= *max_error) > + break; > + } > + > + /* Noisy system timing? */ > + if (i == DRM_TIMESTAMP_MAXRETRIES) { > + DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n", > + pipe, duration_ns/1000, *max_error/1000, i); > + } > + > + /* Return upper bound of timestamp precision error. */ > + *max_error = duration_ns; > + > + /* Convert scanout position into elapsed time at raw_time query > + * since start of scanout at first display scanline. delta_ns > + * can be negative if start of scanout hasn't happened yet. > + */ > + delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), > + mode->crtc_clock); > + > + /* Subtract time delta from raw timestamp to get final > + * vblank_time timestamp for end of vblank. > + */ > + *vblank_time = ktime_sub_ns(etime, delta_ns); > + > + if (!drm_debug_enabled(DRM_UT_VBL)) > + return true; > + > + ts_etime = ktime_to_timespec64(etime); > + ts_vblank_time = ktime_to_timespec64(*vblank_time); > + > + DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us, %d rep]\n", > + pipe, hpos, vpos, > + (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000, > + (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000, > + duration_ns / 1000, i); > + > + return true; > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp_internal); This looks like copy paste from the current thing. Why are you duplicating the entire function instead of refactoring what we already have? > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp - precise vblank timestamp > + * helper > + * @crtc: CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Implements calculation of exact vblank timestamps from given drm_display_mode > + * timings and current video scanout position of a CRTC. This can be directly > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * > + * The current implementation only handles standard video modes. For double scan > + * and interlaced modes the driver is supposed to adjust the hardware mode > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers) to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq) > +{ > + return drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + crtc, max_error, vblank_time, in_vblank_irq, > + crtc->helper_private->get_scanout_position); > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp); > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index 5e9b15a0e8c5..db46abbbf4e7 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -867,6 +867,47 @@ struct drm_crtc_funcs { > * new drivers as the replacement of &drm_driver.disable_vblank hook. > */ > void (*disable_vblank)(struct drm_crtc *crtc); > + > + /** > + * @get_vblank_timestamp: > + * > + * Called by drm_get_last_vbltimestamp(). Should return a precise > + * timestamp when the most recent vblank interval ended or will end. > + * > + * Specifically, the timestamp in @vblank_time should correspond as > + * closely as possible to the time when the first video scanline of > + * the video frame after the end of vblank will start scanning out, > + * the time immediately after end of the vblank interval. If the > + * @crtc is currently inside vblank, this will be a time in the future. > + * If the @crtc is currently scanning out a frame, this will be the > + * past start time of the current scanout. This is meant to adhere > + * to the OpenML OML_sync_control extension specification. > + * > + * Parameters: > + * > + * crtc: > + * CRTC for which timestamp should be returned. > + * max_error: > + * Maximum allowable timestamp error in nanoseconds. > + * Implementation should strive to provide timestamp > + * with an error of at most max_error nanoseconds. > + * Returns true upper bound on error for timestamp. > + * vblank_time: > + * Target location for returned vblank timestamp. > + * in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Returns: > + * > + * True on success, false on failure, which means the core should > + * fallback to a simple timestamp taken in drm_crtc_handle_vblank(). > + */ > + bool (*get_vblank_timestamp)(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > }; > > /** > @@ -974,11 +1015,12 @@ struct drm_crtc { > * Programmed mode in hw, after adjustments for encoders, crtc, panel > * scaling etc. Should only be used by legacy drivers, for high > * precision vblank timestamps in > - * drm_calc_vbltimestamp_from_scanoutpos(). > + * drm_crtc_vblank_helper_get_vblank_timestamp(). > * > * Note that atomic drivers should not use this, but instead use > * &drm_crtc_state.adjusted_mode. And for high-precision timestamps > - * drm_calc_vbltimestamp_from_scanoutpos() used &drm_vblank_crtc.hwmode, > + * drm_crtc_vblank_helper_get_vblank_timestamp() used > + * &drm_vblank_crtc.hwmode, > * which is filled out by calling drm_calc_timestamping_constants(). > */ > struct drm_display_mode hwmode; > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > index e398512bfd5f..0afaf58da40d 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -459,8 +459,8 @@ struct drm_crtc_helper_funcs { > * Returns the current display scanout position from a CRTC and an > * optional accurate ktime_get() timestamp of when the position was > * measured. Note that this is a helper callback which is only used > - * if a driver uses drm_calc_vbltimestamp_from_scanoutpos() for the > - * @drm_driver.get_vblank_timestamp callback. > + * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() > + * for the @drm_crtc_funcs.get_vblank_timestamp callback. > * > * Parameters: > * > diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h > index c16c44052b3d..248fbd5de177 100644 > --- a/include/drm/drm_vblank.h > +++ b/include/drm/drm_vblank.h > @@ -174,13 +174,13 @@ struct drm_vblank_crtc { > unsigned int pipe; > /** > * @framedur_ns: Frame/Field duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int framedur_ns; > /** > * @linedur_ns: Line duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int linedur_ns; > @@ -190,8 +190,8 @@ struct drm_vblank_crtc { > * > * Cache of the current hardware display mode. Only valid when @enabled > * is set. This is used by helpers like > - * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the > - * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > + * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access > + * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > * because that one is really hard to get from interrupt context. > */ > struct drm_display_mode hwmode; > @@ -238,4 +238,22 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc, > wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); > void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, > u32 max_vblank_count); > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode)); Ugly alignment. Could maybe add a typedef for the function pointer if it otherwise gets super horrible with proper alignment. > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > + > #endif > -- > 2.24.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= Subject: Re: [Intel-gfx] [PATCH v2 03/21] drm: Add get_vblank_timestamp() to struct drm_crtc_funcs Date: Wed, 15 Jan 2020 16:49:38 +0200 Message-ID: <20200115144938.GA13686@intel.com> References: <20200115121652.7050-1-tzimmermann@suse.de> <20200115121652.7050-4-tzimmermann@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Return-path: Content-Disposition: inline In-Reply-To: <20200115121652.7050-4-tzimmermann@suse.de> Sender: linux-arm-msm-owner@vger.kernel.org To: Thomas Zimmermann Cc: airlied@linux.ie, daniel@ffwll.ch, alexander.deucher@amd.com, christian.koenig@amd.com, David1.Zhou@amd.com, maarten.lankhorst@linux.intel.com, patrik.r.jakobsson@gmail.com, robdclark@gmail.com, sean@poorly.run, benjamin.gaignard@linaro.org, vincent.abriou@st.com, yannick.fertre@st.com, philippe.cornu@st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, eric@anholt.net, rodrigosiqueiramelo@gmail.com, hamohammed.sa@gmail.com, linux-graphics-maintainer@vmware.com, thellstrom@vmware.com, bskeggs@redhat.com, harry.wentland@amd.com, sunpeng.li@amd.com, jani.nikula@linux.intel.com, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, nouveau@lists.fre List-Id: nouveau.vger.kernel.org On Wed, Jan 15, 2020 at 01:16:34PM +0100, Thomas Zimmermann wrote: > The callback get_vblank_timestamp() is currently located in struct > drm_driver, but really belongs into struct drm_crtc_funcs. Add an > equivalent there. Driver will be converted in separate patches. > > The default implementation is drm_calc_vbltimestamp_from_scanoutpos(). > The patch adds drm_crtc_vblank_helper_get_vblank_timestamp(), which is > an implementation for the CRTC callback. > > v2: > * rename helper to drm_crtc_vblank_helper_get_vblank_timestamp() > * replace drm_calc_vbltimestamp_from_scanoutpos() with > drm_crtc_vblank_helper_get_vblank_timestamp() in docs > > Signed-off-by: Thomas Zimmermann > --- > drivers/gpu/drm/drm_vblank.c | 236 +++++++++++++++++++++-- > include/drm/drm_crtc.h | 46 ++++- > include/drm/drm_modeset_helper_vtables.h | 4 +- > include/drm/drm_vblank.h | 26 ++- > 4 files changed, 292 insertions(+), 20 deletions(-) > > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index abb085c67d82..1b7af316e6a5 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -333,7 +333,9 @@ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *crtc) > u64 vblank; > unsigned long flags; > > - WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !dev->driver->get_vblank_timestamp, > + WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && > + !crtc->funcs->get_vblank_timestamp && > + !dev->driver->get_vblank_timestamp, > "This function requires support for accurate vblank timestamps."); > > spin_lock_irqsave(&dev->vblank_time_lock, flags); > @@ -511,9 +513,9 @@ EXPORT_SYMBOL(drm_crtc_vblank_waitqueue); > * > * Calculate and store various constants which are later needed by vblank and > * swap-completion timestamping, e.g, by > - * drm_calc_vbltimestamp_from_scanoutpos(). They are derived from CRTC's true > - * scanout timing, so they take things like panel scaling or other adjustments > - * into account. > + * drm_crtc_vblank_helper_get_vblank_timestamp(). They are derived from > + * CRTC's true scanout timing, so they take things like panel scaling or > + * other adjustments into account. > */ > void drm_calc_timestamping_constants(struct drm_crtc *crtc, > const struct drm_display_mode *mode) > @@ -577,8 +579,9 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants); > * > * Implements calculation of exact vblank timestamps from given drm_display_mode > * timings and current video scanout position of a CRTC. This can be directly > - * used as the &drm_driver.get_vblank_timestamp implementation of a kms driver > - * if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position or > + * &drm_driver.get_scanout_position is implemented. > * > * The current implementation only handles standard video modes. For double scan > * and interlaced modes the driver is supposed to adjust the hardware mode > @@ -742,15 +745,22 @@ static bool > drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, > ktime_t *tvblank, bool in_vblank_irq) > { > + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); > bool ret = false; > > /* Define requested maximum error on timestamps (nanoseconds). */ > int max_error = (int) drm_timestamp_precision * 1000; > > /* Query driver if possible and precision timestamping enabled. */ > - if (dev->driver->get_vblank_timestamp && (max_error > 0)) > + if (crtc->funcs->get_vblank_timestamp && (max_error > 0)) { Could drop the superfluous parens while at it. Are all drivers utilizing this guaranteed to have the crtc here? > + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); > + > + ret = crtc->funcs->get_vblank_timestamp(crtc, &max_error, > + tvblank, in_vblank_irq); > + } else if (dev->driver->get_vblank_timestamp && (max_error > 0)) { > ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error, > tvblank, in_vblank_irq); > + } > > /* GPU high precision timestamp query unsupported or failed. > * Return current monotonic/gettimeofday timestamp as best estimate. > @@ -1059,11 +1069,19 @@ EXPORT_SYMBOL(drm_crtc_vblank_get); > > static bool __vblank_disable_immediate(struct drm_device *dev, unsigned int pipe) > { > + struct drm_crtc *crtc; > + > if (!dev->vblank_disable_immediate) > return false; > - if (!dev->driver->get_vblank_timestamp) > - return false; > - return true; > + > + crtc = drm_crtc_from_index(dev, pipe); > + if (crtc && crtc->funcs->get_vblank_timestamp) Here you are expecting that the crtc might be NULL. > + return true; > + > + if (dev->driver->get_vblank_timestamp) > + return true; > + > + return false; > } > > static void drm_vblank_put(struct drm_device *dev, unsigned int pipe) > @@ -1742,9 +1760,11 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data, > > static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe) > { > + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); > struct drm_pending_vblank_event *e, *t; > ktime_t now; > u64 seq; > + bool high_prec; > > assert_spin_locked(&dev->event_lock); > > @@ -1764,8 +1784,10 @@ static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe) > send_vblank_event(dev, e, seq, now); > } > > - trace_drm_vblank_event(pipe, seq, now, > - dev->driver->get_vblank_timestamp != NULL); > + high_prec = crtc->funcs->get_vblank_timestamp || > + dev->driver->get_vblank_timestamp; Here again assuming the crtc can't be NULL. > + > + trace_drm_vblank_event(pipe, seq, now, high_prec); > } > > /** > @@ -2020,3 +2042,193 @@ int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data, > kfree(e); > return ret; > } > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp_internal - precise vblank > + * timestamp helper > + * @dev: DRM device > + * @pipe: index of CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * @get_scanout_position: > + * Callback function to retrieve the scanout position. See > + * @struct drm_crtc_helper_funcs.get_scanout_position. > + * > + * Implements calculation of exact vblank timestamps from given drm_display_mode > + * timings and current video scanout position of a CRTC. > + * > + * The current implementation only handles standard video modes. For double scan > + * and interlaced modes the driver is supposed to adjust the hardware mode > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers) to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode)) > +{ > + struct drm_device *dev = crtc->dev; > + unsigned int pipe = crtc->index; > + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; > + struct timespec64 ts_etime, ts_vblank_time; > + ktime_t stime, etime; > + bool vbl_status; > + const struct drm_display_mode *mode; > + int vpos, hpos, i; > + int delta_ns, duration_ns; > + > + if (pipe >= dev->num_crtcs) { > + DRM_ERROR("Invalid crtc %u\n", pipe); > + return false; > + } > + > + /* Scanout position query not supported? Should not happen. */ > + if (!get_scanout_position) { > + DRM_ERROR("Called from CRTC w/o get_scanout_position()!?\n"); > + return false; > + } > + > + if (drm_drv_uses_atomic_modeset(dev)) > + mode = &vblank->hwmode; > + else > + mode = &crtc->hwmode; > + > + /* If mode timing undefined, just return as no-op: > + * Happens during initial modesetting of a crtc. > + */ > + if (mode->crtc_clock == 0) { > + DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe); > + WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev)); > + return false; > + } > + > + /* Get current scanout position with system timestamp. > + * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times > + * if single query takes longer than max_error nanoseconds. > + * > + * This guarantees a tight bound on maximum error if > + * code gets preempted or delayed for some reason. > + */ > + for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { > + /* > + * Get vertical and horizontal scanout position vpos, hpos, > + * and bounding timestamps stime, etime, pre/post query. > + */ > + vbl_status = get_scanout_position(crtc, in_vblank_irq, &vpos, > + &hpos, &stime, &etime, mode); > + > + /* Return as no-op if scanout query unsupported or failed. */ > + if (!vbl_status) { > + DRM_DEBUG("crtc %u : scanoutpos query failed.\n", > + pipe); > + return false; > + } > + > + /* Compute uncertainty in timestamp of scanout position query. */ > + duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime); > + > + /* Accept result with < max_error nsecs timing uncertainty. */ > + if (duration_ns <= *max_error) > + break; > + } > + > + /* Noisy system timing? */ > + if (i == DRM_TIMESTAMP_MAXRETRIES) { > + DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n", > + pipe, duration_ns/1000, *max_error/1000, i); > + } > + > + /* Return upper bound of timestamp precision error. */ > + *max_error = duration_ns; > + > + /* Convert scanout position into elapsed time at raw_time query > + * since start of scanout at first display scanline. delta_ns > + * can be negative if start of scanout hasn't happened yet. > + */ > + delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), > + mode->crtc_clock); > + > + /* Subtract time delta from raw timestamp to get final > + * vblank_time timestamp for end of vblank. > + */ > + *vblank_time = ktime_sub_ns(etime, delta_ns); > + > + if (!drm_debug_enabled(DRM_UT_VBL)) > + return true; > + > + ts_etime = ktime_to_timespec64(etime); > + ts_vblank_time = ktime_to_timespec64(*vblank_time); > + > + DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us, %d rep]\n", > + pipe, hpos, vpos, > + (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000, > + (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000, > + duration_ns / 1000, i); > + > + return true; > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp_internal); This looks like copy paste from the current thing. Why are you duplicating the entire function instead of refactoring what we already have? > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp - precise vblank timestamp > + * helper > + * @crtc: CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Implements calculation of exact vblank timestamps from given drm_display_mode > + * timings and current video scanout position of a CRTC. This can be directly > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * > + * The current implementation only handles standard video modes. For double scan > + * and interlaced modes the driver is supposed to adjust the hardware mode > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers) to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq) > +{ > + return drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + crtc, max_error, vblank_time, in_vblank_irq, > + crtc->helper_private->get_scanout_position); > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp); > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index 5e9b15a0e8c5..db46abbbf4e7 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -867,6 +867,47 @@ struct drm_crtc_funcs { > * new drivers as the replacement of &drm_driver.disable_vblank hook. > */ > void (*disable_vblank)(struct drm_crtc *crtc); > + > + /** > + * @get_vblank_timestamp: > + * > + * Called by drm_get_last_vbltimestamp(). Should return a precise > + * timestamp when the most recent vblank interval ended or will end. > + * > + * Specifically, the timestamp in @vblank_time should correspond as > + * closely as possible to the time when the first video scanline of > + * the video frame after the end of vblank will start scanning out, > + * the time immediately after end of the vblank interval. If the > + * @crtc is currently inside vblank, this will be a time in the future. > + * If the @crtc is currently scanning out a frame, this will be the > + * past start time of the current scanout. This is meant to adhere > + * to the OpenML OML_sync_control extension specification. > + * > + * Parameters: > + * > + * crtc: > + * CRTC for which timestamp should be returned. > + * max_error: > + * Maximum allowable timestamp error in nanoseconds. > + * Implementation should strive to provide timestamp > + * with an error of at most max_error nanoseconds. > + * Returns true upper bound on error for timestamp. > + * vblank_time: > + * Target location for returned vblank timestamp. > + * in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Returns: > + * > + * True on success, false on failure, which means the core should > + * fallback to a simple timestamp taken in drm_crtc_handle_vblank(). > + */ > + bool (*get_vblank_timestamp)(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > }; > > /** > @@ -974,11 +1015,12 @@ struct drm_crtc { > * Programmed mode in hw, after adjustments for encoders, crtc, panel > * scaling etc. Should only be used by legacy drivers, for high > * precision vblank timestamps in > - * drm_calc_vbltimestamp_from_scanoutpos(). > + * drm_crtc_vblank_helper_get_vblank_timestamp(). > * > * Note that atomic drivers should not use this, but instead use > * &drm_crtc_state.adjusted_mode. And for high-precision timestamps > - * drm_calc_vbltimestamp_from_scanoutpos() used &drm_vblank_crtc.hwmode, > + * drm_crtc_vblank_helper_get_vblank_timestamp() used > + * &drm_vblank_crtc.hwmode, > * which is filled out by calling drm_calc_timestamping_constants(). > */ > struct drm_display_mode hwmode; > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_modeset_helper_vtables.h > index e398512bfd5f..0afaf58da40d 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -459,8 +459,8 @@ struct drm_crtc_helper_funcs { > * Returns the current display scanout position from a CRTC and an > * optional accurate ktime_get() timestamp of when the position was > * measured. Note that this is a helper callback which is only used > - * if a driver uses drm_calc_vbltimestamp_from_scanoutpos() for the > - * @drm_driver.get_vblank_timestamp callback. > + * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() > + * for the @drm_crtc_funcs.get_vblank_timestamp callback. > * > * Parameters: > * > diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h > index c16c44052b3d..248fbd5de177 100644 > --- a/include/drm/drm_vblank.h > +++ b/include/drm/drm_vblank.h > @@ -174,13 +174,13 @@ struct drm_vblank_crtc { > unsigned int pipe; > /** > * @framedur_ns: Frame/Field duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int framedur_ns; > /** > * @linedur_ns: Line duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int linedur_ns; > @@ -190,8 +190,8 @@ struct drm_vblank_crtc { > * > * Cache of the current hardware display mode. Only valid when @enabled > * is set. This is used by helpers like > - * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the > - * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > + * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access > + * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > * because that one is really hard to get from interrupt context. > */ > struct drm_display_mode hwmode; > @@ -238,4 +238,22 @@ void drm_calc_timestamping_constants(struct drm_crtc *crtc, > wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); > void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, > u32 max_vblank_count); > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode)); Ugly alignment. Could maybe add a typedef for the function pointer if it otherwise gets super horrible with proper alignment. > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > + > #endif > -- > 2.24.1 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- Ville Syrjälä Intel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C97DC33CB7 for ; Wed, 15 Jan 2020 14:49:50 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 68401222C3 for ; Wed, 15 Jan 2020 14:49:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 68401222C3 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 4718D6EACA; Wed, 15 Jan 2020 14:49:49 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id BCE4B6EAC8; Wed, 15 Jan 2020 14:49:47 +0000 (UTC) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jan 2020 06:49:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,322,1574150400"; d="scan'208";a="253818572" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by fmsmga001.fm.intel.com with SMTP; 15 Jan 2020 06:49:39 -0800 Received: by stinkbox (sSMTP sendmail emulation); Wed, 15 Jan 2020 16:49:38 +0200 Date: Wed, 15 Jan 2020 16:49:38 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Thomas Zimmermann Subject: Re: [Intel-gfx] [PATCH v2 03/21] drm: Add get_vblank_timestamp() to struct drm_crtc_funcs Message-ID: <20200115144938.GA13686@intel.com> References: <20200115121652.7050-1-tzimmermann@suse.de> <20200115121652.7050-4-tzimmermann@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200115121652.7050-4-tzimmermann@suse.de> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hamohammed.sa@gmail.com, airlied@linux.ie, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, alexandre.torgue@st.com, thellstrom@vmware.com, sean@poorly.run, linux-graphics-maintainer@vmware.com, bskeggs@redhat.com, mcoquelin.stm32@gmail.com, sunpeng.li@amd.com, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, rodrigo.vivi@intel.com, vincent.abriou@st.com, rodrigosiqueiramelo@gmail.com, philippe.cornu@st.com, yannick.fertre@st.com, alexander.deucher@amd.com, freedreno@lists.freedesktop.org, christian.koenig@amd.com Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Jan 15, 2020 at 01:16:34PM +0100, Thomas Zimmermann wrote: > The callback get_vblank_timestamp() is currently located in struct > drm_driver, but really belongs into struct drm_crtc_funcs. Add an > equivalent there. Driver will be converted in separate patches. > = > The default implementation is drm_calc_vbltimestamp_from_scanoutpos(). > The patch adds drm_crtc_vblank_helper_get_vblank_timestamp(), which is > an implementation for the CRTC callback. > = > v2: > * rename helper to drm_crtc_vblank_helper_get_vblank_timestamp() > * replace drm_calc_vbltimestamp_from_scanoutpos() with > drm_crtc_vblank_helper_get_vblank_timestamp() in docs > = > Signed-off-by: Thomas Zimmermann > --- > drivers/gpu/drm/drm_vblank.c | 236 +++++++++++++++++++++-- > include/drm/drm_crtc.h | 46 ++++- > include/drm/drm_modeset_helper_vtables.h | 4 +- > include/drm/drm_vblank.h | 26 ++- > 4 files changed, 292 insertions(+), 20 deletions(-) > = > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index abb085c67d82..1b7af316e6a5 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -333,7 +333,9 @@ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *c= rtc) > u64 vblank; > unsigned long flags; > = > - WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !dev->driver->get_vblank_tim= estamp, > + WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && > + !crtc->funcs->get_vblank_timestamp && > + !dev->driver->get_vblank_timestamp, > "This function requires support for accurate vblank timestamps."); > = > spin_lock_irqsave(&dev->vblank_time_lock, flags); > @@ -511,9 +513,9 @@ EXPORT_SYMBOL(drm_crtc_vblank_waitqueue); > * > * Calculate and store various constants which are later needed by vblan= k and > * swap-completion timestamping, e.g, by > - * drm_calc_vbltimestamp_from_scanoutpos(). They are derived from CRTC's= true > - * scanout timing, so they take things like panel scaling or other adjus= tments > - * into account. > + * drm_crtc_vblank_helper_get_vblank_timestamp(). They are derived from > + * CRTC's true scanout timing, so they take things like panel scaling or > + * other adjustments into account. > */ > void drm_calc_timestamping_constants(struct drm_crtc *crtc, > const struct drm_display_mode *mode) > @@ -577,8 +579,9 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants); > * > * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > * timings and current video scanout position of a CRTC. This can be dir= ectly > - * used as the &drm_driver.get_vblank_timestamp implementation of a kms = driver > - * if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a = kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position or > + * &drm_driver.get_scanout_position is implemented. > * > * The current implementation only handles standard video modes. For dou= ble scan > * and interlaced modes the driver is supposed to adjust the hardware mo= de > @@ -742,15 +745,22 @@ static bool > drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, > ktime_t *tvblank, bool in_vblank_irq) > { > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > bool ret =3D false; > = > /* Define requested maximum error on timestamps (nanoseconds). */ > int max_error =3D (int) drm_timestamp_precision * 1000; > = > /* Query driver if possible and precision timestamping enabled. */ > - if (dev->driver->get_vblank_timestamp && (max_error > 0)) > + if (crtc->funcs->get_vblank_timestamp && (max_error > 0)) { Could drop the superfluous parens while at it. Are all drivers utilizing this guaranteed to have the crtc here? > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > + > + ret =3D crtc->funcs->get_vblank_timestamp(crtc, &max_error, > + tvblank, in_vblank_irq); > + } else if (dev->driver->get_vblank_timestamp && (max_error > 0)) { > ret =3D dev->driver->get_vblank_timestamp(dev, pipe, &max_error, > tvblank, in_vblank_irq); > + } > = > /* GPU high precision timestamp query unsupported or failed. > * Return current monotonic/gettimeofday timestamp as best estimate. > @@ -1059,11 +1069,19 @@ EXPORT_SYMBOL(drm_crtc_vblank_get); > = > static bool __vblank_disable_immediate(struct drm_device *dev, unsigned = int pipe) > { > + struct drm_crtc *crtc; > + > if (!dev->vblank_disable_immediate) > return false; > - if (!dev->driver->get_vblank_timestamp) > - return false; > - return true; > + > + crtc =3D drm_crtc_from_index(dev, pipe); > + if (crtc && crtc->funcs->get_vblank_timestamp) Here you are expecting that the crtc might be NULL. > + return true; > + > + if (dev->driver->get_vblank_timestamp) > + return true; > + > + return false; > } > = > static void drm_vblank_put(struct drm_device *dev, unsigned int pipe) > @@ -1742,9 +1760,11 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, = void *data, > = > static void drm_handle_vblank_events(struct drm_device *dev, unsigned in= t pipe) > { > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > struct drm_pending_vblank_event *e, *t; > ktime_t now; > u64 seq; > + bool high_prec; > = > assert_spin_locked(&dev->event_lock); > = > @@ -1764,8 +1784,10 @@ static void drm_handle_vblank_events(struct drm_de= vice *dev, unsigned int pipe) > send_vblank_event(dev, e, seq, now); > } > = > - trace_drm_vblank_event(pipe, seq, now, > - dev->driver->get_vblank_timestamp !=3D NULL); > + high_prec =3D crtc->funcs->get_vblank_timestamp || > + dev->driver->get_vblank_timestamp; Here again assuming the crtc can't be NULL. > + > + trace_drm_vblank_event(pipe, seq, now, high_prec); > } > = > /** > @@ -2020,3 +2042,193 @@ int drm_crtc_queue_sequence_ioctl(struct drm_devi= ce *dev, void *data, > kfree(e); > return ret; > } > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp_internal - precise vblank > + * timestamp help= er > + * @dev: DRM device > + * @pipe: index of CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * @get_scanout_position: > + * Callback function to retrieve the scanout position. See > + * @struct drm_crtc_helper_funcs.get_scanout_position. > + * > + * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > + * timings and current video scanout position of a CRTC. > + * > + * The current implementation only handles standard video modes. For dou= ble scan > + * and interlaced modes the driver is supposed to adjust the hardware mo= de > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers)= to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() = before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int = *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode= )) > +{ > + struct drm_device *dev =3D crtc->dev; > + unsigned int pipe =3D crtc->index; > + struct drm_vblank_crtc *vblank =3D &dev->vblank[pipe]; > + struct timespec64 ts_etime, ts_vblank_time; > + ktime_t stime, etime; > + bool vbl_status; > + const struct drm_display_mode *mode; > + int vpos, hpos, i; > + int delta_ns, duration_ns; > + > + if (pipe >=3D dev->num_crtcs) { > + DRM_ERROR("Invalid crtc %u\n", pipe); > + return false; > + } > + > + /* Scanout position query not supported? Should not happen. */ > + if (!get_scanout_position) { > + DRM_ERROR("Called from CRTC w/o get_scanout_position()!?\n"); > + return false; > + } > + > + if (drm_drv_uses_atomic_modeset(dev)) > + mode =3D &vblank->hwmode; > + else > + mode =3D &crtc->hwmode; > + > + /* If mode timing undefined, just return as no-op: > + * Happens during initial modesetting of a crtc. > + */ > + if (mode->crtc_clock =3D=3D 0) { > + DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe); > + WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev)); > + return false; > + } > + > + /* Get current scanout position with system timestamp. > + * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times > + * if single query takes longer than max_error nanoseconds. > + * > + * This guarantees a tight bound on maximum error if > + * code gets preempted or delayed for some reason. > + */ > + for (i =3D 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { > + /* > + * Get vertical and horizontal scanout position vpos, hpos, > + * and bounding timestamps stime, etime, pre/post query. > + */ > + vbl_status =3D get_scanout_position(crtc, in_vblank_irq, &vpos, > + &hpos, &stime, &etime, mode); > + > + /* Return as no-op if scanout query unsupported or failed. */ > + if (!vbl_status) { > + DRM_DEBUG("crtc %u : scanoutpos query failed.\n", > + pipe); > + return false; > + } > + > + /* Compute uncertainty in timestamp of scanout position query. */ > + duration_ns =3D ktime_to_ns(etime) - ktime_to_ns(stime); > + > + /* Accept result with < max_error nsecs timing uncertainty. */ > + if (duration_ns <=3D *max_error) > + break; > + } > + > + /* Noisy system timing? */ > + if (i =3D=3D DRM_TIMESTAMP_MAXRETRIES) { > + DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n", > + pipe, duration_ns/1000, *max_error/1000, i); > + } > + > + /* Return upper bound of timestamp precision error. */ > + *max_error =3D duration_ns; > + > + /* Convert scanout position into elapsed time at raw_time query > + * since start of scanout at first display scanline. delta_ns > + * can be negative if start of scanout hasn't happened yet. > + */ > + delta_ns =3D div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), > + mode->crtc_clock); > + > + /* Subtract time delta from raw timestamp to get final > + * vblank_time timestamp for end of vblank. > + */ > + *vblank_time =3D ktime_sub_ns(etime, delta_ns); > + > + if (!drm_debug_enabled(DRM_UT_VBL)) > + return true; > + > + ts_etime =3D ktime_to_timespec64(etime); > + ts_vblank_time =3D ktime_to_timespec64(*vblank_time); > + > + DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us,= %d rep]\n", > + pipe, hpos, vpos, > + (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000, > + (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000, > + duration_ns / 1000, i); > + > + return true; > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp_internal); This looks like copy paste from the current thing. Why are you = duplicating the entire function instead of refactoring what we already have? > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp - precise vblank timestamp > + * helper > + * @crtc: CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > + * timings and current video scanout position of a CRTC. This can be dir= ectly > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a = kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * > + * The current implementation only handles standard video modes. For dou= ble scan > + * and interlaced modes the driver is supposed to adjust the hardware mo= de > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers)= to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() = before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq) > +{ > + return drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + crtc, max_error, vblank_time, in_vblank_irq, > + crtc->helper_private->get_scanout_position); > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp); > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index 5e9b15a0e8c5..db46abbbf4e7 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -867,6 +867,47 @@ struct drm_crtc_funcs { > * new drivers as the replacement of &drm_driver.disable_vblank hook. > */ > void (*disable_vblank)(struct drm_crtc *crtc); > + > + /** > + * @get_vblank_timestamp: > + * > + * Called by drm_get_last_vbltimestamp(). Should return a precise > + * timestamp when the most recent vblank interval ended or will end. > + * > + * Specifically, the timestamp in @vblank_time should correspond as > + * closely as possible to the time when the first video scanline of > + * the video frame after the end of vblank will start scanning out, > + * the time immediately after end of the vblank interval. If the > + * @crtc is currently inside vblank, this will be a time in the future. > + * If the @crtc is currently scanning out a frame, this will be the > + * past start time of the current scanout. This is meant to adhere > + * to the OpenML OML_sync_control extension specification. > + * > + * Parameters: > + * > + * crtc: > + * CRTC for which timestamp should be returned. > + * max_error: > + * Maximum allowable timestamp error in nanoseconds. > + * Implementation should strive to provide timestamp > + * with an error of at most max_error nanoseconds. > + * Returns true upper bound on error for timestamp. > + * vblank_time: > + * Target location for returned vblank timestamp. > + * in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Returns: > + * > + * True on success, false on failure, which means the core should > + * fallback to a simple timestamp taken in drm_crtc_handle_vblank(). > + */ > + bool (*get_vblank_timestamp)(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > }; > = > /** > @@ -974,11 +1015,12 @@ struct drm_crtc { > * Programmed mode in hw, after adjustments for encoders, crtc, panel > * scaling etc. Should only be used by legacy drivers, for high > * precision vblank timestamps in > - * drm_calc_vbltimestamp_from_scanoutpos(). > + * drm_crtc_vblank_helper_get_vblank_timestamp(). > * > * Note that atomic drivers should not use this, but instead use > * &drm_crtc_state.adjusted_mode. And for high-precision timestamps > - * drm_calc_vbltimestamp_from_scanoutpos() used &drm_vblank_crtc.hwmode, > + * drm_crtc_vblank_helper_get_vblank_timestamp() used > + * &drm_vblank_crtc.hwmode, > * which is filled out by calling drm_calc_timestamping_constants(). > */ > struct drm_display_mode hwmode; > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_m= odeset_helper_vtables.h > index e398512bfd5f..0afaf58da40d 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -459,8 +459,8 @@ struct drm_crtc_helper_funcs { > * Returns the current display scanout position from a CRTC and an > * optional accurate ktime_get() timestamp of when the position was > * measured. Note that this is a helper callback which is only used > - * if a driver uses drm_calc_vbltimestamp_from_scanoutpos() for the > - * @drm_driver.get_vblank_timestamp callback. > + * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() > + * for the @drm_crtc_funcs.get_vblank_timestamp callback. > * > * Parameters: > * > diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h > index c16c44052b3d..248fbd5de177 100644 > --- a/include/drm/drm_vblank.h > +++ b/include/drm/drm_vblank.h > @@ -174,13 +174,13 @@ struct drm_vblank_crtc { > unsigned int pipe; > /** > * @framedur_ns: Frame/Field duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int framedur_ns; > /** > * @linedur_ns: Line duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int linedur_ns; > @@ -190,8 +190,8 @@ struct drm_vblank_crtc { > * > * Cache of the current hardware display mode. Only valid when @enabled > * is set. This is used by helpers like > - * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the > - * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > + * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access > + * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > * because that one is really hard to get from interrupt context. > */ > struct drm_display_mode hwmode; > @@ -238,4 +238,22 @@ void drm_calc_timestamping_constants(struct drm_crtc= *crtc, > wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); > void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, > u32 max_vblank_count); > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int = *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode= )); Ugly alignment. Could maybe add a typedef for the function pointer if it otherwise gets super horrible with proper alignment. > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > + > #endif > -- = > 2.24.1 > = > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- = Ville Syrj=E4l=E4 Intel _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1702CC33CB2 for ; Wed, 15 Jan 2020 14:49:56 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EB3D9214AF for ; Wed, 15 Jan 2020 14:49:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EB3D9214AF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=intel-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 8F7A86EACC; Wed, 15 Jan 2020 14:49:49 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id BCE4B6EAC8; Wed, 15 Jan 2020 14:49:47 +0000 (UTC) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jan 2020 06:49:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,322,1574150400"; d="scan'208";a="253818572" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by fmsmga001.fm.intel.com with SMTP; 15 Jan 2020 06:49:39 -0800 Received: by stinkbox (sSMTP sendmail emulation); Wed, 15 Jan 2020 16:49:38 +0200 Date: Wed, 15 Jan 2020 16:49:38 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Thomas Zimmermann Message-ID: <20200115144938.GA13686@intel.com> References: <20200115121652.7050-1-tzimmermann@suse.de> <20200115121652.7050-4-tzimmermann@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200115121652.7050-4-tzimmermann@suse.de> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) Subject: Re: [Intel-gfx] [PATCH v2 03/21] drm: Add get_vblank_timestamp() to struct drm_crtc_funcs X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hamohammed.sa@gmail.com, airlied@linux.ie, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, eric@anholt.net, amd-gfx@lists.freedesktop.org, benjamin.gaignard@linaro.org, alexandre.torgue@st.com, David1.Zhou@amd.com, thellstrom@vmware.com, linux-graphics-maintainer@vmware.com, bskeggs@redhat.com, harry.wentland@amd.com, mcoquelin.stm32@gmail.com, sunpeng.li@amd.com, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, vincent.abriou@st.com, rodrigosiqueiramelo@gmail.com, philippe.cornu@st.com, yannick.fertre@st.com, alexander.deucher@amd.com, freedreno@lists.freedesktop.org, christian.koenig@amd.com Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Wed, Jan 15, 2020 at 01:16:34PM +0100, Thomas Zimmermann wrote: > The callback get_vblank_timestamp() is currently located in struct > drm_driver, but really belongs into struct drm_crtc_funcs. Add an > equivalent there. Driver will be converted in separate patches. > = > The default implementation is drm_calc_vbltimestamp_from_scanoutpos(). > The patch adds drm_crtc_vblank_helper_get_vblank_timestamp(), which is > an implementation for the CRTC callback. > = > v2: > * rename helper to drm_crtc_vblank_helper_get_vblank_timestamp() > * replace drm_calc_vbltimestamp_from_scanoutpos() with > drm_crtc_vblank_helper_get_vblank_timestamp() in docs > = > Signed-off-by: Thomas Zimmermann > --- > drivers/gpu/drm/drm_vblank.c | 236 +++++++++++++++++++++-- > include/drm/drm_crtc.h | 46 ++++- > include/drm/drm_modeset_helper_vtables.h | 4 +- > include/drm/drm_vblank.h | 26 ++- > 4 files changed, 292 insertions(+), 20 deletions(-) > = > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index abb085c67d82..1b7af316e6a5 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -333,7 +333,9 @@ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *c= rtc) > u64 vblank; > unsigned long flags; > = > - WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !dev->driver->get_vblank_tim= estamp, > + WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && > + !crtc->funcs->get_vblank_timestamp && > + !dev->driver->get_vblank_timestamp, > "This function requires support for accurate vblank timestamps."); > = > spin_lock_irqsave(&dev->vblank_time_lock, flags); > @@ -511,9 +513,9 @@ EXPORT_SYMBOL(drm_crtc_vblank_waitqueue); > * > * Calculate and store various constants which are later needed by vblan= k and > * swap-completion timestamping, e.g, by > - * drm_calc_vbltimestamp_from_scanoutpos(). They are derived from CRTC's= true > - * scanout timing, so they take things like panel scaling or other adjus= tments > - * into account. > + * drm_crtc_vblank_helper_get_vblank_timestamp(). They are derived from > + * CRTC's true scanout timing, so they take things like panel scaling or > + * other adjustments into account. > */ > void drm_calc_timestamping_constants(struct drm_crtc *crtc, > const struct drm_display_mode *mode) > @@ -577,8 +579,9 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants); > * > * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > * timings and current video scanout position of a CRTC. This can be dir= ectly > - * used as the &drm_driver.get_vblank_timestamp implementation of a kms = driver > - * if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a = kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position or > + * &drm_driver.get_scanout_position is implemented. > * > * The current implementation only handles standard video modes. For dou= ble scan > * and interlaced modes the driver is supposed to adjust the hardware mo= de > @@ -742,15 +745,22 @@ static bool > drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, > ktime_t *tvblank, bool in_vblank_irq) > { > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > bool ret =3D false; > = > /* Define requested maximum error on timestamps (nanoseconds). */ > int max_error =3D (int) drm_timestamp_precision * 1000; > = > /* Query driver if possible and precision timestamping enabled. */ > - if (dev->driver->get_vblank_timestamp && (max_error > 0)) > + if (crtc->funcs->get_vblank_timestamp && (max_error > 0)) { Could drop the superfluous parens while at it. Are all drivers utilizing this guaranteed to have the crtc here? > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > + > + ret =3D crtc->funcs->get_vblank_timestamp(crtc, &max_error, > + tvblank, in_vblank_irq); > + } else if (dev->driver->get_vblank_timestamp && (max_error > 0)) { > ret =3D dev->driver->get_vblank_timestamp(dev, pipe, &max_error, > tvblank, in_vblank_irq); > + } > = > /* GPU high precision timestamp query unsupported or failed. > * Return current monotonic/gettimeofday timestamp as best estimate. > @@ -1059,11 +1069,19 @@ EXPORT_SYMBOL(drm_crtc_vblank_get); > = > static bool __vblank_disable_immediate(struct drm_device *dev, unsigned = int pipe) > { > + struct drm_crtc *crtc; > + > if (!dev->vblank_disable_immediate) > return false; > - if (!dev->driver->get_vblank_timestamp) > - return false; > - return true; > + > + crtc =3D drm_crtc_from_index(dev, pipe); > + if (crtc && crtc->funcs->get_vblank_timestamp) Here you are expecting that the crtc might be NULL. > + return true; > + > + if (dev->driver->get_vblank_timestamp) > + return true; > + > + return false; > } > = > static void drm_vblank_put(struct drm_device *dev, unsigned int pipe) > @@ -1742,9 +1760,11 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, = void *data, > = > static void drm_handle_vblank_events(struct drm_device *dev, unsigned in= t pipe) > { > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > struct drm_pending_vblank_event *e, *t; > ktime_t now; > u64 seq; > + bool high_prec; > = > assert_spin_locked(&dev->event_lock); > = > @@ -1764,8 +1784,10 @@ static void drm_handle_vblank_events(struct drm_de= vice *dev, unsigned int pipe) > send_vblank_event(dev, e, seq, now); > } > = > - trace_drm_vblank_event(pipe, seq, now, > - dev->driver->get_vblank_timestamp !=3D NULL); > + high_prec =3D crtc->funcs->get_vblank_timestamp || > + dev->driver->get_vblank_timestamp; Here again assuming the crtc can't be NULL. > + > + trace_drm_vblank_event(pipe, seq, now, high_prec); > } > = > /** > @@ -2020,3 +2042,193 @@ int drm_crtc_queue_sequence_ioctl(struct drm_devi= ce *dev, void *data, > kfree(e); > return ret; > } > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp_internal - precise vblank > + * timestamp help= er > + * @dev: DRM device > + * @pipe: index of CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * @get_scanout_position: > + * Callback function to retrieve the scanout position. See > + * @struct drm_crtc_helper_funcs.get_scanout_position. > + * > + * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > + * timings and current video scanout position of a CRTC. > + * > + * The current implementation only handles standard video modes. For dou= ble scan > + * and interlaced modes the driver is supposed to adjust the hardware mo= de > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers)= to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() = before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int = *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode= )) > +{ > + struct drm_device *dev =3D crtc->dev; > + unsigned int pipe =3D crtc->index; > + struct drm_vblank_crtc *vblank =3D &dev->vblank[pipe]; > + struct timespec64 ts_etime, ts_vblank_time; > + ktime_t stime, etime; > + bool vbl_status; > + const struct drm_display_mode *mode; > + int vpos, hpos, i; > + int delta_ns, duration_ns; > + > + if (pipe >=3D dev->num_crtcs) { > + DRM_ERROR("Invalid crtc %u\n", pipe); > + return false; > + } > + > + /* Scanout position query not supported? Should not happen. */ > + if (!get_scanout_position) { > + DRM_ERROR("Called from CRTC w/o get_scanout_position()!?\n"); > + return false; > + } > + > + if (drm_drv_uses_atomic_modeset(dev)) > + mode =3D &vblank->hwmode; > + else > + mode =3D &crtc->hwmode; > + > + /* If mode timing undefined, just return as no-op: > + * Happens during initial modesetting of a crtc. > + */ > + if (mode->crtc_clock =3D=3D 0) { > + DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe); > + WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev)); > + return false; > + } > + > + /* Get current scanout position with system timestamp. > + * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times > + * if single query takes longer than max_error nanoseconds. > + * > + * This guarantees a tight bound on maximum error if > + * code gets preempted or delayed for some reason. > + */ > + for (i =3D 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { > + /* > + * Get vertical and horizontal scanout position vpos, hpos, > + * and bounding timestamps stime, etime, pre/post query. > + */ > + vbl_status =3D get_scanout_position(crtc, in_vblank_irq, &vpos, > + &hpos, &stime, &etime, mode); > + > + /* Return as no-op if scanout query unsupported or failed. */ > + if (!vbl_status) { > + DRM_DEBUG("crtc %u : scanoutpos query failed.\n", > + pipe); > + return false; > + } > + > + /* Compute uncertainty in timestamp of scanout position query. */ > + duration_ns =3D ktime_to_ns(etime) - ktime_to_ns(stime); > + > + /* Accept result with < max_error nsecs timing uncertainty. */ > + if (duration_ns <=3D *max_error) > + break; > + } > + > + /* Noisy system timing? */ > + if (i =3D=3D DRM_TIMESTAMP_MAXRETRIES) { > + DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n", > + pipe, duration_ns/1000, *max_error/1000, i); > + } > + > + /* Return upper bound of timestamp precision error. */ > + *max_error =3D duration_ns; > + > + /* Convert scanout position into elapsed time at raw_time query > + * since start of scanout at first display scanline. delta_ns > + * can be negative if start of scanout hasn't happened yet. > + */ > + delta_ns =3D div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), > + mode->crtc_clock); > + > + /* Subtract time delta from raw timestamp to get final > + * vblank_time timestamp for end of vblank. > + */ > + *vblank_time =3D ktime_sub_ns(etime, delta_ns); > + > + if (!drm_debug_enabled(DRM_UT_VBL)) > + return true; > + > + ts_etime =3D ktime_to_timespec64(etime); > + ts_vblank_time =3D ktime_to_timespec64(*vblank_time); > + > + DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us,= %d rep]\n", > + pipe, hpos, vpos, > + (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000, > + (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000, > + duration_ns / 1000, i); > + > + return true; > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp_internal); This looks like copy paste from the current thing. Why are you = duplicating the entire function instead of refactoring what we already have? > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp - precise vblank timestamp > + * helper > + * @crtc: CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > + * timings and current video scanout position of a CRTC. This can be dir= ectly > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a = kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * > + * The current implementation only handles standard video modes. For dou= ble scan > + * and interlaced modes the driver is supposed to adjust the hardware mo= de > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers)= to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() = before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq) > +{ > + return drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + crtc, max_error, vblank_time, in_vblank_irq, > + crtc->helper_private->get_scanout_position); > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp); > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index 5e9b15a0e8c5..db46abbbf4e7 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -867,6 +867,47 @@ struct drm_crtc_funcs { > * new drivers as the replacement of &drm_driver.disable_vblank hook. > */ > void (*disable_vblank)(struct drm_crtc *crtc); > + > + /** > + * @get_vblank_timestamp: > + * > + * Called by drm_get_last_vbltimestamp(). Should return a precise > + * timestamp when the most recent vblank interval ended or will end. > + * > + * Specifically, the timestamp in @vblank_time should correspond as > + * closely as possible to the time when the first video scanline of > + * the video frame after the end of vblank will start scanning out, > + * the time immediately after end of the vblank interval. If the > + * @crtc is currently inside vblank, this will be a time in the future. > + * If the @crtc is currently scanning out a frame, this will be the > + * past start time of the current scanout. This is meant to adhere > + * to the OpenML OML_sync_control extension specification. > + * > + * Parameters: > + * > + * crtc: > + * CRTC for which timestamp should be returned. > + * max_error: > + * Maximum allowable timestamp error in nanoseconds. > + * Implementation should strive to provide timestamp > + * with an error of at most max_error nanoseconds. > + * Returns true upper bound on error for timestamp. > + * vblank_time: > + * Target location for returned vblank timestamp. > + * in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Returns: > + * > + * True on success, false on failure, which means the core should > + * fallback to a simple timestamp taken in drm_crtc_handle_vblank(). > + */ > + bool (*get_vblank_timestamp)(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > }; > = > /** > @@ -974,11 +1015,12 @@ struct drm_crtc { > * Programmed mode in hw, after adjustments for encoders, crtc, panel > * scaling etc. Should only be used by legacy drivers, for high > * precision vblank timestamps in > - * drm_calc_vbltimestamp_from_scanoutpos(). > + * drm_crtc_vblank_helper_get_vblank_timestamp(). > * > * Note that atomic drivers should not use this, but instead use > * &drm_crtc_state.adjusted_mode. And for high-precision timestamps > - * drm_calc_vbltimestamp_from_scanoutpos() used &drm_vblank_crtc.hwmode, > + * drm_crtc_vblank_helper_get_vblank_timestamp() used > + * &drm_vblank_crtc.hwmode, > * which is filled out by calling drm_calc_timestamping_constants(). > */ > struct drm_display_mode hwmode; > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_m= odeset_helper_vtables.h > index e398512bfd5f..0afaf58da40d 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -459,8 +459,8 @@ struct drm_crtc_helper_funcs { > * Returns the current display scanout position from a CRTC and an > * optional accurate ktime_get() timestamp of when the position was > * measured. Note that this is a helper callback which is only used > - * if a driver uses drm_calc_vbltimestamp_from_scanoutpos() for the > - * @drm_driver.get_vblank_timestamp callback. > + * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() > + * for the @drm_crtc_funcs.get_vblank_timestamp callback. > * > * Parameters: > * > diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h > index c16c44052b3d..248fbd5de177 100644 > --- a/include/drm/drm_vblank.h > +++ b/include/drm/drm_vblank.h > @@ -174,13 +174,13 @@ struct drm_vblank_crtc { > unsigned int pipe; > /** > * @framedur_ns: Frame/Field duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int framedur_ns; > /** > * @linedur_ns: Line duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int linedur_ns; > @@ -190,8 +190,8 @@ struct drm_vblank_crtc { > * > * Cache of the current hardware display mode. Only valid when @enabled > * is set. This is used by helpers like > - * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the > - * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > + * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access > + * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > * because that one is really hard to get from interrupt context. > */ > struct drm_display_mode hwmode; > @@ -238,4 +238,22 @@ void drm_calc_timestamping_constants(struct drm_crtc= *crtc, > wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); > void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, > u32 max_vblank_count); > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int = *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode= )); Ugly alignment. Could maybe add a typedef for the function pointer if it otherwise gets super horrible with proper alignment. > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > + > #endif > -- = > 2.24.1 > = > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- = Ville Syrj=E4l=E4 Intel _______________________________________________ Intel-gfx mailing list Intel-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/intel-gfx From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 39304C33CB1 for ; Wed, 15 Jan 2020 14:49:55 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 161D7214AF for ; Wed, 15 Jan 2020 14:49:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 161D7214AF Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=amd-gfx-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AE62B6EACD; Wed, 15 Jan 2020 14:49:49 +0000 (UTC) Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id BCE4B6EAC8; Wed, 15 Jan 2020 14:49:47 +0000 (UTC) X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by fmsmga103.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 15 Jan 2020 06:49:47 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,322,1574150400"; d="scan'208";a="253818572" Received: from stinkbox.fi.intel.com (HELO stinkbox) ([10.237.72.174]) by fmsmga001.fm.intel.com with SMTP; 15 Jan 2020 06:49:39 -0800 Received: by stinkbox (sSMTP sendmail emulation); Wed, 15 Jan 2020 16:49:38 +0200 Date: Wed, 15 Jan 2020 16:49:38 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Thomas Zimmermann Subject: Re: [Intel-gfx] [PATCH v2 03/21] drm: Add get_vblank_timestamp() to struct drm_crtc_funcs Message-ID: <20200115144938.GA13686@intel.com> References: <20200115121652.7050-1-tzimmermann@suse.de> <20200115121652.7050-4-tzimmermann@suse.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200115121652.7050-4-tzimmermann@suse.de> X-Patchwork-Hint: comment User-Agent: Mutt/1.10.1 (2018-07-13) X-BeenThere: amd-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussion list for AMD gfx List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: hamohammed.sa@gmail.com, airlied@linux.ie, nouveau@lists.freedesktop.org, joonas.lahtinen@linux.intel.com, dri-devel@lists.freedesktop.org, eric@anholt.net, amd-gfx@lists.freedesktop.org, benjamin.gaignard@linaro.org, alexandre.torgue@st.com, David1.Zhou@amd.com, thellstrom@vmware.com, sean@poorly.run, patrik.r.jakobsson@gmail.com, linux-graphics-maintainer@vmware.com, bskeggs@redhat.com, harry.wentland@amd.com, mcoquelin.stm32@gmail.com, sunpeng.li@amd.com, linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, maarten.lankhorst@linux.intel.com, jani.nikula@linux.intel.com, rodrigo.vivi@intel.com, vincent.abriou@st.com, rodrigosiqueiramelo@gmail.com, philippe.cornu@st.com, yannick.fertre@st.com, robdclark@gmail.com, daniel@ffwll.ch, alexander.deucher@amd.com, freedreno@lists.freedesktop.org, christian.koenig@amd.com Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: amd-gfx-bounces@lists.freedesktop.org Sender: "amd-gfx" On Wed, Jan 15, 2020 at 01:16:34PM +0100, Thomas Zimmermann wrote: > The callback get_vblank_timestamp() is currently located in struct > drm_driver, but really belongs into struct drm_crtc_funcs. Add an > equivalent there. Driver will be converted in separate patches. > = > The default implementation is drm_calc_vbltimestamp_from_scanoutpos(). > The patch adds drm_crtc_vblank_helper_get_vblank_timestamp(), which is > an implementation for the CRTC callback. > = > v2: > * rename helper to drm_crtc_vblank_helper_get_vblank_timestamp() > * replace drm_calc_vbltimestamp_from_scanoutpos() with > drm_crtc_vblank_helper_get_vblank_timestamp() in docs > = > Signed-off-by: Thomas Zimmermann > --- > drivers/gpu/drm/drm_vblank.c | 236 +++++++++++++++++++++-- > include/drm/drm_crtc.h | 46 ++++- > include/drm/drm_modeset_helper_vtables.h | 4 +- > include/drm/drm_vblank.h | 26 ++- > 4 files changed, 292 insertions(+), 20 deletions(-) > = > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index abb085c67d82..1b7af316e6a5 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -333,7 +333,9 @@ u64 drm_crtc_accurate_vblank_count(struct drm_crtc *c= rtc) > u64 vblank; > unsigned long flags; > = > - WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && !dev->driver->get_vblank_tim= estamp, > + WARN_ONCE(drm_debug_enabled(DRM_UT_VBL) && > + !crtc->funcs->get_vblank_timestamp && > + !dev->driver->get_vblank_timestamp, > "This function requires support for accurate vblank timestamps."); > = > spin_lock_irqsave(&dev->vblank_time_lock, flags); > @@ -511,9 +513,9 @@ EXPORT_SYMBOL(drm_crtc_vblank_waitqueue); > * > * Calculate and store various constants which are later needed by vblan= k and > * swap-completion timestamping, e.g, by > - * drm_calc_vbltimestamp_from_scanoutpos(). They are derived from CRTC's= true > - * scanout timing, so they take things like panel scaling or other adjus= tments > - * into account. > + * drm_crtc_vblank_helper_get_vblank_timestamp(). They are derived from > + * CRTC's true scanout timing, so they take things like panel scaling or > + * other adjustments into account. > */ > void drm_calc_timestamping_constants(struct drm_crtc *crtc, > const struct drm_display_mode *mode) > @@ -577,8 +579,9 @@ EXPORT_SYMBOL(drm_calc_timestamping_constants); > * > * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > * timings and current video scanout position of a CRTC. This can be dir= ectly > - * used as the &drm_driver.get_vblank_timestamp implementation of a kms = driver > - * if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a = kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position or > + * &drm_driver.get_scanout_position is implemented. > * > * The current implementation only handles standard video modes. For dou= ble scan > * and interlaced modes the driver is supposed to adjust the hardware mo= de > @@ -742,15 +745,22 @@ static bool > drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, > ktime_t *tvblank, bool in_vblank_irq) > { > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > bool ret =3D false; > = > /* Define requested maximum error on timestamps (nanoseconds). */ > int max_error =3D (int) drm_timestamp_precision * 1000; > = > /* Query driver if possible and precision timestamping enabled. */ > - if (dev->driver->get_vblank_timestamp && (max_error > 0)) > + if (crtc->funcs->get_vblank_timestamp && (max_error > 0)) { Could drop the superfluous parens while at it. Are all drivers utilizing this guaranteed to have the crtc here? > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > + > + ret =3D crtc->funcs->get_vblank_timestamp(crtc, &max_error, > + tvblank, in_vblank_irq); > + } else if (dev->driver->get_vblank_timestamp && (max_error > 0)) { > ret =3D dev->driver->get_vblank_timestamp(dev, pipe, &max_error, > tvblank, in_vblank_irq); > + } > = > /* GPU high precision timestamp query unsupported or failed. > * Return current monotonic/gettimeofday timestamp as best estimate. > @@ -1059,11 +1069,19 @@ EXPORT_SYMBOL(drm_crtc_vblank_get); > = > static bool __vblank_disable_immediate(struct drm_device *dev, unsigned = int pipe) > { > + struct drm_crtc *crtc; > + > if (!dev->vblank_disable_immediate) > return false; > - if (!dev->driver->get_vblank_timestamp) > - return false; > - return true; > + > + crtc =3D drm_crtc_from_index(dev, pipe); > + if (crtc && crtc->funcs->get_vblank_timestamp) Here you are expecting that the crtc might be NULL. > + return true; > + > + if (dev->driver->get_vblank_timestamp) > + return true; > + > + return false; > } > = > static void drm_vblank_put(struct drm_device *dev, unsigned int pipe) > @@ -1742,9 +1760,11 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, = void *data, > = > static void drm_handle_vblank_events(struct drm_device *dev, unsigned in= t pipe) > { > + struct drm_crtc *crtc =3D drm_crtc_from_index(dev, pipe); > struct drm_pending_vblank_event *e, *t; > ktime_t now; > u64 seq; > + bool high_prec; > = > assert_spin_locked(&dev->event_lock); > = > @@ -1764,8 +1784,10 @@ static void drm_handle_vblank_events(struct drm_de= vice *dev, unsigned int pipe) > send_vblank_event(dev, e, seq, now); > } > = > - trace_drm_vblank_event(pipe, seq, now, > - dev->driver->get_vblank_timestamp !=3D NULL); > + high_prec =3D crtc->funcs->get_vblank_timestamp || > + dev->driver->get_vblank_timestamp; Here again assuming the crtc can't be NULL. > + > + trace_drm_vblank_event(pipe, seq, now, high_prec); > } > = > /** > @@ -2020,3 +2042,193 @@ int drm_crtc_queue_sequence_ioctl(struct drm_devi= ce *dev, void *data, > kfree(e); > return ret; > } > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp_internal - precise vblank > + * timestamp help= er > + * @dev: DRM device > + * @pipe: index of CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * @get_scanout_position: > + * Callback function to retrieve the scanout position. See > + * @struct drm_crtc_helper_funcs.get_scanout_position. > + * > + * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > + * timings and current video scanout position of a CRTC. > + * > + * The current implementation only handles standard video modes. For dou= ble scan > + * and interlaced modes the driver is supposed to adjust the hardware mo= de > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers)= to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() = before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int = *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode= )) > +{ > + struct drm_device *dev =3D crtc->dev; > + unsigned int pipe =3D crtc->index; > + struct drm_vblank_crtc *vblank =3D &dev->vblank[pipe]; > + struct timespec64 ts_etime, ts_vblank_time; > + ktime_t stime, etime; > + bool vbl_status; > + const struct drm_display_mode *mode; > + int vpos, hpos, i; > + int delta_ns, duration_ns; > + > + if (pipe >=3D dev->num_crtcs) { > + DRM_ERROR("Invalid crtc %u\n", pipe); > + return false; > + } > + > + /* Scanout position query not supported? Should not happen. */ > + if (!get_scanout_position) { > + DRM_ERROR("Called from CRTC w/o get_scanout_position()!?\n"); > + return false; > + } > + > + if (drm_drv_uses_atomic_modeset(dev)) > + mode =3D &vblank->hwmode; > + else > + mode =3D &crtc->hwmode; > + > + /* If mode timing undefined, just return as no-op: > + * Happens during initial modesetting of a crtc. > + */ > + if (mode->crtc_clock =3D=3D 0) { > + DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe); > + WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev)); > + return false; > + } > + > + /* Get current scanout position with system timestamp. > + * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times > + * if single query takes longer than max_error nanoseconds. > + * > + * This guarantees a tight bound on maximum error if > + * code gets preempted or delayed for some reason. > + */ > + for (i =3D 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { > + /* > + * Get vertical and horizontal scanout position vpos, hpos, > + * and bounding timestamps stime, etime, pre/post query. > + */ > + vbl_status =3D get_scanout_position(crtc, in_vblank_irq, &vpos, > + &hpos, &stime, &etime, mode); > + > + /* Return as no-op if scanout query unsupported or failed. */ > + if (!vbl_status) { > + DRM_DEBUG("crtc %u : scanoutpos query failed.\n", > + pipe); > + return false; > + } > + > + /* Compute uncertainty in timestamp of scanout position query. */ > + duration_ns =3D ktime_to_ns(etime) - ktime_to_ns(stime); > + > + /* Accept result with < max_error nsecs timing uncertainty. */ > + if (duration_ns <=3D *max_error) > + break; > + } > + > + /* Noisy system timing? */ > + if (i =3D=3D DRM_TIMESTAMP_MAXRETRIES) { > + DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n", > + pipe, duration_ns/1000, *max_error/1000, i); > + } > + > + /* Return upper bound of timestamp precision error. */ > + *max_error =3D duration_ns; > + > + /* Convert scanout position into elapsed time at raw_time query > + * since start of scanout at first display scanline. delta_ns > + * can be negative if start of scanout hasn't happened yet. > + */ > + delta_ns =3D div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), > + mode->crtc_clock); > + > + /* Subtract time delta from raw timestamp to get final > + * vblank_time timestamp for end of vblank. > + */ > + *vblank_time =3D ktime_sub_ns(etime, delta_ns); > + > + if (!drm_debug_enabled(DRM_UT_VBL)) > + return true; > + > + ts_etime =3D ktime_to_timespec64(etime); > + ts_vblank_time =3D ktime_to_timespec64(*vblank_time); > + > + DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %lld.%06ld -> %lld.%06ld [e %d us,= %d rep]\n", > + pipe, hpos, vpos, > + (u64)ts_etime.tv_sec, ts_etime.tv_nsec / 1000, > + (u64)ts_vblank_time.tv_sec, ts_vblank_time.tv_nsec / 1000, > + duration_ns / 1000, i); > + > + return true; > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp_internal); This looks like copy paste from the current thing. Why are you = duplicating the entire function instead of refactoring what we already have? > + > +/** > + * drm_crtc_vblank_helper_get_vblank_timestamp - precise vblank timestamp > + * helper > + * @crtc: CRTC whose vblank timestamp to retrieve > + * @max_error: Desired maximum allowable error in timestamps (nanosecs) > + * On return contains true maximum error of timestamp > + * @vblank_time: Pointer to time which should receive the timestamp > + * @in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Implements calculation of exact vblank timestamps from given drm_disp= lay_mode > + * timings and current video scanout position of a CRTC. This can be dir= ectly > + * used as the &drm_crtc_funcs.get_vblank_timestamp implementation of a = kms > + * driver if &drm_crtc_helper_funcs.get_scanout_position is implemented. > + * > + * The current implementation only handles standard video modes. For dou= ble scan > + * and interlaced modes the driver is supposed to adjust the hardware mo= de > + * (taken from &drm_crtc_state.adjusted mode for atomic modeset drivers)= to > + * match the scanout position reported. > + * > + * Note that atomic drivers must call drm_calc_timestamping_constants() = before > + * enabling a CRTC. The atomic helpers already take care of that in > + * drm_atomic_helper_update_legacy_modeset_state(). > + * > + * Returns: > + * > + * Returns true on success, and false on failure, i.e. when no accurate > + * timestamp could be acquired. > + */ > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq) > +{ > + return drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + crtc, max_error, vblank_time, in_vblank_irq, > + crtc->helper_private->get_scanout_position); > +} > +EXPORT_SYMBOL(drm_crtc_vblank_helper_get_vblank_timestamp); > diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h > index 5e9b15a0e8c5..db46abbbf4e7 100644 > --- a/include/drm/drm_crtc.h > +++ b/include/drm/drm_crtc.h > @@ -867,6 +867,47 @@ struct drm_crtc_funcs { > * new drivers as the replacement of &drm_driver.disable_vblank hook. > */ > void (*disable_vblank)(struct drm_crtc *crtc); > + > + /** > + * @get_vblank_timestamp: > + * > + * Called by drm_get_last_vbltimestamp(). Should return a precise > + * timestamp when the most recent vblank interval ended or will end. > + * > + * Specifically, the timestamp in @vblank_time should correspond as > + * closely as possible to the time when the first video scanline of > + * the video frame after the end of vblank will start scanning out, > + * the time immediately after end of the vblank interval. If the > + * @crtc is currently inside vblank, this will be a time in the future. > + * If the @crtc is currently scanning out a frame, this will be the > + * past start time of the current scanout. This is meant to adhere > + * to the OpenML OML_sync_control extension specification. > + * > + * Parameters: > + * > + * crtc: > + * CRTC for which timestamp should be returned. > + * max_error: > + * Maximum allowable timestamp error in nanoseconds. > + * Implementation should strive to provide timestamp > + * with an error of at most max_error nanoseconds. > + * Returns true upper bound on error for timestamp. > + * vblank_time: > + * Target location for returned vblank timestamp. > + * in_vblank_irq: > + * True when called from drm_crtc_handle_vblank(). Some drivers > + * need to apply some workarounds for gpu-specific vblank irq quirks > + * if flag is set. > + * > + * Returns: > + * > + * True on success, false on failure, which means the core should > + * fallback to a simple timestamp taken in drm_crtc_handle_vblank(). > + */ > + bool (*get_vblank_timestamp)(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > }; > = > /** > @@ -974,11 +1015,12 @@ struct drm_crtc { > * Programmed mode in hw, after adjustments for encoders, crtc, panel > * scaling etc. Should only be used by legacy drivers, for high > * precision vblank timestamps in > - * drm_calc_vbltimestamp_from_scanoutpos(). > + * drm_crtc_vblank_helper_get_vblank_timestamp(). > * > * Note that atomic drivers should not use this, but instead use > * &drm_crtc_state.adjusted_mode. And for high-precision timestamps > - * drm_calc_vbltimestamp_from_scanoutpos() used &drm_vblank_crtc.hwmode, > + * drm_crtc_vblank_helper_get_vblank_timestamp() used > + * &drm_vblank_crtc.hwmode, > * which is filled out by calling drm_calc_timestamping_constants(). > */ > struct drm_display_mode hwmode; > diff --git a/include/drm/drm_modeset_helper_vtables.h b/include/drm/drm_m= odeset_helper_vtables.h > index e398512bfd5f..0afaf58da40d 100644 > --- a/include/drm/drm_modeset_helper_vtables.h > +++ b/include/drm/drm_modeset_helper_vtables.h > @@ -459,8 +459,8 @@ struct drm_crtc_helper_funcs { > * Returns the current display scanout position from a CRTC and an > * optional accurate ktime_get() timestamp of when the position was > * measured. Note that this is a helper callback which is only used > - * if a driver uses drm_calc_vbltimestamp_from_scanoutpos() for the > - * @drm_driver.get_vblank_timestamp callback. > + * if a driver uses drm_crtc_vblank_helper_get_vblank_timestamp() > + * for the @drm_crtc_funcs.get_vblank_timestamp callback. > * > * Parameters: > * > diff --git a/include/drm/drm_vblank.h b/include/drm/drm_vblank.h > index c16c44052b3d..248fbd5de177 100644 > --- a/include/drm/drm_vblank.h > +++ b/include/drm/drm_vblank.h > @@ -174,13 +174,13 @@ struct drm_vblank_crtc { > unsigned int pipe; > /** > * @framedur_ns: Frame/Field duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int framedur_ns; > /** > * @linedur_ns: Line duration in ns, used by > - * drm_calc_vbltimestamp_from_scanoutpos() and computed by > + * drm_crtc_vblank_helper_get_vblank_timestamp() and computed by > * drm_calc_timestamping_constants(). > */ > int linedur_ns; > @@ -190,8 +190,8 @@ struct drm_vblank_crtc { > * > * Cache of the current hardware display mode. Only valid when @enabled > * is set. This is used by helpers like > - * drm_calc_vbltimestamp_from_scanoutpos(). We can't just access the > - * hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > + * drm_crtc_vblank_helper_get_vblank_timestamp(). We can't just access > + * the hardware mode by e.g. looking at &drm_crtc_state.adjusted_mode, > * because that one is really hard to get from interrupt context. > */ > struct drm_display_mode hwmode; > @@ -238,4 +238,22 @@ void drm_calc_timestamping_constants(struct drm_crtc= *crtc, > wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc); > void drm_crtc_set_max_vblank_count(struct drm_crtc *crtc, > u32 max_vblank_count); > + > +/* > + * Helpers for struct drm_crtc_funcs > + */ > + > +bool > +drm_crtc_vblank_helper_get_vblank_timestamp_internal( > + struct drm_crtc *crtc, int *max_error, ktime_t *vblank_time, > + bool in_vblank_irq, > + bool (*get_scanout_position)(struct drm_crtc *crtc, > + bool in_vblank_irq, int *vpos, int = *hpos, > + ktime_t *stime, ktime_t *etime, > + const struct drm_display_mode *mode= )); Ugly alignment. Could maybe add a typedef for the function pointer if it otherwise gets super horrible with proper alignment. > +bool drm_crtc_vblank_helper_get_vblank_timestamp(struct drm_crtc *crtc, > + int *max_error, > + ktime_t *vblank_time, > + bool in_vblank_irq); > + > #endif > -- = > 2.24.1 > = > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx -- = Ville Syrj=E4l=E4 Intel _______________________________________________ amd-gfx mailing list amd-gfx@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/amd-gfx