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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 B657CC49EA6 for ; Thu, 24 Jun 2021 08:07:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C381613E7 for ; Thu, 24 Jun 2021 08:07:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231849AbhFXIJU (ORCPT ); Thu, 24 Jun 2021 04:09:20 -0400 Received: from mga11.intel.com ([192.55.52.93]:23517 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231838AbhFXIJU (ORCPT ); Thu, 24 Jun 2021 04:09:20 -0400 IronPort-SDR: KL4erKlKQnF+zZ0KCSWGIpKblHFktwruvFMaOhA4Z1e8Bn6Cq2S7WhRpX/JZa4LuerARriW4av IJgDo2XStwjQ== X-IronPort-AV: E=McAfee;i="6200,9189,10024"; a="204416284" X-IronPort-AV: E=Sophos;i="5.83,296,1616482800"; d="scan'208";a="204416284" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2021 01:06:48 -0700 IronPort-SDR: 8/eo5APk4zdMXu0FN+wLrM/zTggRpAhTnkAmYTRZ+IPR7FPPJCkD/zsI3oSWpDppu7y95aJRLY 6S2bQnOSmTDA== X-IronPort-AV: E=Sophos;i="5.83,296,1616482800"; d="scan'208";a="453335479" Received: from schulke-mobl1.ger.corp.intel.com (HELO localhost) ([10.252.59.242]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Jun 2021 01:06:23 -0700 From: Jani Nikula To: Thomas Zimmermann , daniel@ffwll.ch, airlied@linux.ie, alexander.deucher@amd.com, christian.koenig@amd.com, Xinhui.Pan@amd.com, james.qian.wang@arm.com, liviu.dudau@arm.com, mihail.atanassov@arm.com, brian.starkey@arm.com, maarten.lankhorst@linux.intel.com, mripard@kernel.org, inki.dae@samsung.com, jy0922.shim@samsung.com, sw0312.kim@samsung.com, kyungmin.park@samsung.com, krzysztof.kozlowski@canonical.com, xinliang.liu@linaro.org, tiantao6@hisilicon.com, john.stultz@linaro.org, kong.kongxinwei@hisilicon.com, puck.chen@hisilicon.com, laurentiu.palcu@oss.nxp.com, l.stach@pengutronix.de, p.zabel@pengutronix.de, shawnguo@kernel.org, s.hauer@pengutronix.de, kernel@pengutronix.de, festevam@gmail.com, linux-imx@nxp.com, chunkuang.hu@kernel.org, matthias.bgg@gmail.com, bskeggs@redhat.com, tomba@kernel.org, hjc@rock-chips.com, heiko@sntech.de, benjamin.gaignard@linaro.org, yannick.fertre@foss.st.com, philippe.cornu@foss.st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@foss.st.com, wens@csie.org, jernej.skrabec@gmail.com, thierry.reding@gmail.com, jonathanh@nvidia.com, jyri.sarha@iki.fi, emma@anholt.net, linux-graphics-maintainer@vmware.com, zackr@vmware.com, hyun.kwon@xilinx.com, laurent.pinchart@ideasonboard.com, michal.simek@xilinx.com, rodrigo.vivi@intel.com, linux@armlinux.org.uk, kieran.bingham+renesas@ideasonboard.com, rodrigosiqueiramelo@gmail.com, melissa.srw@gmail.com, hamohammed.sa@gmail.com Cc: amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-mediatek@lists.infradead.org, nouveau@lists.freedesktop.org, linux-rockchip@lists.infradead.org, linux-stm32@st-md-mailman.stormreply.com, linux-sunxi@lists.linux.dev, linux-tegra@vger.kernel.org, intel-gfx@lists.freedesktop.org, Thomas Zimmermann , Daniel Vetter Subject: Re: [PATCH v3 04/27] drm: Don't test for IRQ support in VBLANK ioctls In-Reply-To: <20210624072916.27703-5-tzimmermann@suse.de> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <20210624072916.27703-1-tzimmermann@suse.de> <20210624072916.27703-5-tzimmermann@suse.de> Date: Thu, 24 Jun 2021 11:06:19 +0300 Message-ID: <87im23u1ok.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org On Thu, 24 Jun 2021, Thomas Zimmermann wrote: > For KMS drivers, replace the IRQ check in VBLANK ioctls with a check for > vblank support. IRQs might be enabled wthout vblanking being supported. > > This change also removes the DRM framework's only dependency on IRQ state > for non-legacy drivers. For legacy drivers with userspace modesetting, > the original test remains in drm_wait_vblank_ioctl(). > > v3: > * optimize test in drm_wait_vblank_ioctl() for KMS case (Liviu) > * update docs for drm_irq_uninstall() > v2: > * keep the old test for legacy drivers in > drm_wait_vblank_ioctl() (Daniel) > > Signed-off-by: Thomas Zimmermann > Reviewed-by: Laurent Pinchart > Acked-by: Daniel Vetter > --- > drivers/gpu/drm/drm_irq.c | 13 ++++--------- > drivers/gpu/drm/drm_vblank.c | 16 ++++++++++++---- > 2 files changed, 16 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c > index c3bd664ea733..945dd82e2ea3 100644 > --- a/drivers/gpu/drm/drm_irq.c > +++ b/drivers/gpu/drm/drm_irq.c > @@ -74,10 +74,8 @@ > * only supports devices with a single interrupt on the main device stored in > * &drm_device.dev and set as the device paramter in drm_dev_alloc(). > * > - * These IRQ helpers are strictly optional. Drivers which roll their own only > - * need to set &drm_device.irq_enabled to signal the DRM core that vblank > - * interrupts are working. Since these helpers don't automatically clean up the > - * requested interrupt like e.g. devm_request_irq() they're not really > + * These IRQ helpers are strictly optional. Since these helpers don't automatically > + * clean up the requested interrupt like e.g. devm_request_irq() they're not really > * recommended. > */ > > @@ -91,9 +89,7 @@ > * and after the installation. > * > * This is the simplified helper interface provided for drivers with no special > - * needs. Drivers which need to install interrupt handlers for multiple > - * interrupts must instead set &drm_device.irq_enabled to signal the DRM core > - * that vblank interrupts are available. > + * needs. > * > * @irq must match the interrupt number that would be passed to request_irq(), > * if called directly instead of using this helper function. > @@ -156,8 +152,7 @@ EXPORT_SYMBOL(drm_irq_install); > * > * Calls the driver's &drm_driver.irq_uninstall function and unregisters the IRQ > * handler. This should only be called by drivers which used drm_irq_install() > - * to set up their interrupt handler. Other drivers must only reset > - * &drm_device.irq_enabled to false. > + * to set up their interrupt handler. > * > * Note that for kernel modesetting drivers it is a bug if this function fails. > * The sanity checks are only to catch buggy user modesetting drivers which call > diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c > index 3417e1ac7918..10fe16bafcb6 100644 > --- a/drivers/gpu/drm/drm_vblank.c > +++ b/drivers/gpu/drm/drm_vblank.c > @@ -1748,8 +1748,16 @@ int drm_wait_vblank_ioctl(struct drm_device *dev, void *data, > unsigned int pipe_index; > unsigned int flags, pipe, high_pipe; > > - if (!dev->irq_enabled) > - return -EOPNOTSUPP; > +#if defined(CONFIG_DRM_LEGACY) > + if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) { > + if (!dev->irq_enabled) > + return -EOPNOTSUPP; > + } else /* if DRIVER_MODESET */ > +#endif > + { > + if (!drm_dev_has_vblank(dev)) > + return -EOPNOTSUPP; > + } Sheesh I hate this kind of inline #ifdefs. Two alternate suggestions that I believe should be as just efficient: 1) The more verbose: #if defined(CONFIG_DRM_LEGACY) static bool drm_wait_vblank_supported(struct drm_device *dev) { if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) return dev->irq_enabled; else return drm_dev_has_vblank(dev); } #else static bool drm_wait_vblank_supported(struct drm_device *dev) { return drm_dev_has_vblank(dev); } #endif 2) The more compact: static bool drm_wait_vblank_supported(struct drm_device *dev) { if (IS_ENABLED(CONFIG_DRM_LEGACY) && unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) return dev->irq_enabled; else return drm_dev_has_vblank(dev); } Then, in drm_wait_vblank_ioctl(). if (!drm_wait_vblank_supported(dev)) return -EOPNOTSUPP; The compiler should do the right thing without any explicit inline keywords etc. BR, Jani. > > if (vblwait->request.type & _DRM_VBLANK_SIGNAL) > return -EINVAL; > @@ -2023,7 +2031,7 @@ int drm_crtc_get_sequence_ioctl(struct drm_device *dev, void *data, > if (!drm_core_check_feature(dev, DRIVER_MODESET)) > return -EOPNOTSUPP; > > - if (!dev->irq_enabled) > + if (!drm_dev_has_vblank(dev)) > return -EOPNOTSUPP; > > crtc = drm_crtc_find(dev, file_priv, get_seq->crtc_id); > @@ -2082,7 +2090,7 @@ int drm_crtc_queue_sequence_ioctl(struct drm_device *dev, void *data, > if (!drm_core_check_feature(dev, DRIVER_MODESET)) > return -EOPNOTSUPP; > > - if (!dev->irq_enabled) > + if (!drm_dev_has_vblank(dev)) > return -EOPNOTSUPP; > > crtc = drm_crtc_find(dev, file_priv, queue_seq->crtc_id); -- Jani Nikula, Intel Open Source Graphics Center