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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 3B12FC282DD for ; Fri, 10 Jan 2020 13:56:24 +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 1BD6B2072E for ; Fri, 10 Jan 2020 13:56:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BD6B2072E 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 6993F6EA15; Fri, 10 Jan 2020 13:56:21 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by gabe.freedesktop.org (Postfix) with ESMTPS id BF7586EA02; Fri, 10 Jan 2020 13:56:19 +0000 (UTC) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 05:56:19 -0800 X-IronPort-AV: E=Sophos;i="5.69,417,1571727600"; d="scan'208";a="371616160" Received: from jnikula-mobl3.fi.intel.com (HELO localhost) ([10.237.66.161]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 10 Jan 2020 05:56:08 -0800 From: Jani Nikula To: Thomas Zimmermann , 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, joonas.lahtinen@linux.intel.com, rodrigo.vivi@intel.com Subject: Re: [PATCH 03/23] drm/i915: Don't use struct drm_driver.get_scanout_position() In-Reply-To: <761ae94c-aaf1-9167-9c44-06824304fdfd@suse.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20200110092127.27847-1-tzimmermann@suse.de> <20200110092127.27847-4-tzimmermann@suse.de> <87eew7o73u.fsf@intel.com> <761ae94c-aaf1-9167-9c44-06824304fdfd@suse.de> Date: Fri, 10 Jan 2020 15:56:06 +0200 Message-ID: <875zhjo1op.fsf@intel.com> MIME-Version: 1.0 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: linux-arm-msm@vger.kernel.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, amd-gfx@lists.freedesktop.org, nouveau@lists.freedesktop.org, freedreno@lists.freedesktop.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Fri, 10 Jan 2020, Thomas Zimmermann wrote: > Hi > > Am 10.01.20 um 12:59 schrieb Jani Nikula: >> On Fri, 10 Jan 2020, Thomas Zimmermann wrote: >>> The callback struct drm_driver.get_scanout_position() is deprecated in >>> favor of struct drm_crtc_helper_funcs.get_scanout_position(). >>> >>> i915 doesn't use CRTC helpers. The patch duplicates the caller >>> drm_calc_vbltimestamp_from_scanoutpos() for i915, such that the callback >>> function is not needed. >>> >>> Signed-off-by: Thomas Zimmermann >>> --- >>> drivers/gpu/drm/i915/i915_drv.c | 3 +- >>> drivers/gpu/drm/i915/i915_irq.c | 117 ++++++++++++++++++++++++++++++-- >>> drivers/gpu/drm/i915/i915_irq.h | 9 +-- >>> 3 files changed, 119 insertions(+), 10 deletions(-) >> >> Not really enthusiastic about the diffstat in a "cleanup" series. > > Well, the cleanup is about the content of drm_driver :) > >> >> I wonder if you could add a generic helper version of >> drm_calc_vbltimestamp_from_scanoutpos where you pass the >> get_scanout_position function as a parameter. Both >> drm_calc_vbltimestamp_from_scanoutpos and the new >> i915_calc_vbltimestamp_from_scanoutpos would then be fairly thin >> wrappers passing in the relevant get_scanout_position function. > > Of course. Will be in v2 of the series. Please give Ville (Cc'd) a moment before sending v2 in case he wants to chime in on this. Thanks, Jani. > > Best regards > Thomas > >> >> This would reduce the almost identical duplication of the function in >> i915. >> >> BR, >> Jani. >> >>> >>> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c >>> index f7385abdd74b..4a0a7fb85c53 100644 >>> --- a/drivers/gpu/drm/i915/i915_drv.c >>> +++ b/drivers/gpu/drm/i915/i915_drv.c >>> @@ -2769,8 +2769,7 @@ static struct drm_driver driver = { >>> .gem_prime_export = i915_gem_prime_export, >>> .gem_prime_import = i915_gem_prime_import, >>> >>> - .get_vblank_timestamp = drm_calc_vbltimestamp_from_scanoutpos, >>> - .get_scanout_position = i915_get_crtc_scanoutpos, >>> + .get_vblank_timestamp = i915_calc_vbltimestamp_from_scanoutpos, >>> >>> .dumb_create = i915_gem_dumb_create, >>> .dumb_map_offset = i915_gem_dumb_mmap_offset, >>> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c >>> index afc6aad9bf8c..99d0c3b0feae 100644 >>> --- a/drivers/gpu/drm/i915/i915_irq.c >>> +++ b/drivers/gpu/drm/i915/i915_irq.c >>> @@ -52,6 +52,11 @@ >>> #include "i915_trace.h" >>> #include "intel_pm.h" >>> >>> +/* Retry timestamp calculation up to 3 times to satisfy >>> + * drm_timestamp_precision before giving up. >>> + */ >>> +#define I915_TIMESTAMP_MAXRETRIES 3 >>> + >>> /** >>> * DOC: interrupt handling >>> * >>> @@ -762,10 +767,11 @@ static int __intel_get_crtc_scanline(struct intel_crtc *crtc) >>> return (position + crtc->scanline_offset) % vtotal; >>> } >>> >>> -bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int index, >>> - bool in_vblank_irq, int *vpos, int *hpos, >>> - ktime_t *stime, ktime_t *etime, >>> - const struct drm_display_mode *mode) >>> +static bool i915_get_crtc_scanoutpos(struct drm_device *dev, >>> + unsigned int index, bool in_vblank_irq, >>> + int *vpos, int *hpos, >>> + ktime_t *stime, ktime_t *etime, >>> + const struct drm_display_mode *mode) >>> { >>> struct drm_i915_private *dev_priv = to_i915(dev); >>> struct intel_crtc *crtc = to_intel_crtc(drm_crtc_from_index(dev, index)); >>> @@ -879,6 +885,109 @@ bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int index, >>> return true; >>> } >>> >>> +bool i915_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, >>> + unsigned int pipe, >>> + int *max_error, >>> + ktime_t *vblank_time, >>> + bool in_vblank_irq) >>> +{ >>> + struct timespec64 ts_etime, ts_vblank_time; >>> + ktime_t stime, etime; >>> + bool vbl_status; >>> + struct drm_crtc *crtc; >>> + const struct drm_display_mode *mode; >>> + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; >>> + int vpos, hpos, i; >>> + int delta_ns, duration_ns; >>> + >>> + crtc = drm_crtc_from_index(dev, pipe); >>> + >>> + if (pipe >= dev->num_crtcs || !crtc) { >>> + DRM_ERROR("Invalid crtc %u\n", pipe); >>> + 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 < I915_TIMESTAMP_MAXRETRIES; i++) { >>> + /* >>> + * Get vertical and horizontal scanout position vpos, hpos, >>> + * and bounding timestamps stime, etime, pre/post query. >>> + */ >>> + vbl_status = i915_get_crtc_scanoutpos(dev, pipe, 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 == I915_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; >>> +} >>> + >>> int intel_get_crtc_scanline(struct intel_crtc *crtc) >>> { >>> struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); >>> diff --git a/drivers/gpu/drm/i915/i915_irq.h b/drivers/gpu/drm/i915/i915_irq.h >>> index 812c47a9c2d6..5f7b133ce721 100644 >>> --- a/drivers/gpu/drm/i915/i915_irq.h >>> +++ b/drivers/gpu/drm/i915/i915_irq.h >>> @@ -101,10 +101,11 @@ void gen8_irq_power_well_post_enable(struct drm_i915_private *dev_priv, >>> void gen8_irq_power_well_pre_disable(struct drm_i915_private *dev_priv, >>> u8 pipe_mask); >>> >>> -bool i915_get_crtc_scanoutpos(struct drm_device *dev, unsigned int pipe, >>> - bool in_vblank_irq, int *vpos, int *hpos, >>> - ktime_t *stime, ktime_t *etime, >>> - const struct drm_display_mode *mode); >>> +bool i915_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, >>> + unsigned int pipe, >>> + int *max_error, >>> + ktime_t *vblank_time, >>> + bool in_vblank_irq); >>> >>> u32 i915_get_vblank_counter(struct drm_crtc *crtc); >>> u32 g4x_get_vblank_counter(struct drm_crtc *crtc); >> -- Jani Nikula, Intel Open Source Graphics Center _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel