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bh=0L5nz5bVnzlvJV0RjY8gCyLPBlQHqLtg4oioZgDj7sE=; b=wgWw5+iHWQ5qv3h7jV7wxXmyKHYRMe8CDc7lR0BDGQmqx/Do4XbDkNVtHpd2XiGqlnj6YX 1A74dssIJKaSWNBw== Received: from director2.suse.de ([192.168.254.72]) by imap3-int with ESMTPSA id zwiRLUtC1GBNIQAALh3uQQ (envelope-from ); Thu, 24 Jun 2021 08:28:59 +0000 Subject: Re: [PATCH v3 04/27] drm: Don't test for IRQ support in VBLANK ioctls To: Jani Nikula , 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: linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-sunxi@lists.linux.dev, linux-rockchip@lists.infradead.org, linux-mediatek@lists.infradead.org, amd-gfx@lists.freedesktop.org, Daniel Vetter , linux-tegra@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org References: <20210624072916.27703-1-tzimmermann@suse.de> <20210624072916.27703-5-tzimmermann@suse.de> <87im23u1ok.fsf@intel.com> From: Thomas Zimmermann Message-ID: Date: Thu, 24 Jun 2021 10:28:59 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: <87im23u1ok.fsf@intel.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="XeS7eJ5JPg7IwjZ7mWHplNVbGBiq1dAM5" Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --XeS7eJ5JPg7IwjZ7mWHplNVbGBiq1dAM5 Content-Type: multipart/mixed; boundary="zYjFVN6LbQJto7YyRvmktHhbjS3oGNxBZ"; protected-headers="v1" From: Thomas Zimmermann To: Jani Nikula , 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: linux-samsung-soc@vger.kernel.org, nouveau@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-sunxi@lists.linux.dev, linux-rockchip@lists.infradead.org, linux-mediatek@lists.infradead.org, amd-gfx@lists.freedesktop.org, Daniel Vetter , linux-tegra@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Message-ID: Subject: Re: [PATCH v3 04/27] drm: Don't test for IRQ support in VBLANK ioctls References: <20210624072916.27703-1-tzimmermann@suse.de> <20210624072916.27703-5-tzimmermann@suse.de> <87im23u1ok.fsf@intel.com> In-Reply-To: <87im23u1ok.fsf@intel.com> --zYjFVN6LbQJto7YyRvmktHhbjS3oGNxBZ Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable Hi Am 24.06.21 um 10:06 schrieb Jani Nikula: > On Thu, 24 Jun 2021, Thomas Zimmermann wrote: >> For KMS drivers, replace the IRQ check in VBLANK ioctls with a check f= or >> vblank support. IRQs might be enabled wthout vblanking being supported= =2E >> >> This change also removes the DRM framework's only dependency on IRQ st= ate >> 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()= =2E >> * >> - * 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 vb= lank >> - * interrupts are working. Since these helpers don't automatically cl= ean up the >> - * requested interrupt like e.g. devm_request_irq() they're not reall= y >> + * 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. >> */ >> =20 >> @@ -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 multip= le >> - * 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 requ= est_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 unregis= ters the IRQ >> * handler. This should only be called by drivers which used drm_ir= q_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 func= tion fails. >> * The sanity checks are only to catch buggy user modesetting driver= s which call >> diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank= =2Ec >> 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 *de= v, void *data, >> unsigned int pipe_index; >> unsigned int flags, pipe, high_pipe; >> =20 >> - 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; >> + } >=20 > Sheesh I hate this kind of inline #ifdefs. >=20 > Two alternate suggestions that I believe should be as just efficient: Or how about: static bool drm_wait_vblank_supported(struct drm_device *dev) { if defined(CONFIG_DRM_LEGACY) if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) return dev->irq_enabled; #endif return drm_dev_has_vblank(dev); } ? It's inline, but still readable. Best regards Thomas >=20 > 1) The more verbose: >=20 > #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 >=20 > 2) The more compact: >=20 > 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); > } >=20 > Then, in drm_wait_vblank_ioctl(). >=20 > if (!drm_wait_vblank_supported(dev)) > return -EOPNOTSUPP; >=20 > The compiler should do the right thing without any explicit inline > keywords etc. >=20 > BR, > Jani. >=20 >> =20 >> if (vblwait->request.type & _DRM_VBLANK_SIGNAL) >> return -EINVAL; >> @@ -2023,7 +2031,7 @@ int drm_crtc_get_sequence_ioctl(struct drm_devic= e *dev, void *data, >> if (!drm_core_check_feature(dev, DRIVER_MODESET)) >> return -EOPNOTSUPP; >> =20 >> - if (!dev->irq_enabled) >> + if (!drm_dev_has_vblank(dev)) >> return -EOPNOTSUPP; >> =20 >> crtc =3D drm_crtc_find(dev, file_priv, get_seq->crtc_id); >> @@ -2082,7 +2090,7 @@ int drm_crtc_queue_sequence_ioctl(struct drm_dev= ice *dev, void *data, >> if (!drm_core_check_feature(dev, DRIVER_MODESET)) >> return -EOPNOTSUPP; >> =20 >> - if (!dev->irq_enabled) >> + if (!drm_dev_has_vblank(dev)) >> return -EOPNOTSUPP; >> =20 >> crtc =3D drm_crtc_find(dev, file_priv, queue_seq->crtc_id); >=20 --=20 Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 N=C3=BCrnberg, Germany (HRB 36809, AG N=C3=BCrnberg) Gesch=C3=A4ftsf=C3=BChrer: Felix Imend=C3=B6rffer --zYjFVN6LbQJto7YyRvmktHhbjS3oGNxBZ-- --XeS7eJ5JPg7IwjZ7mWHplNVbGBiq1dAM5 Content-Type: application/pgp-signature; name="OpenPGP_signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="OpenPGP_signature" -----BEGIN PGP SIGNATURE----- wsF5BAABCAAjFiEExndm/fpuMUdwYFFolh/E3EQov+AFAmDUQksFAwAAAAAACgkQlh/E3EQov+CO tBAAscKEApzwALsL/afbcm5uKvx5iVv2dEDtvThHqwM/vLySjYR97Sf8prBBklUa9XgOJYT3X8rC c0t3Uzq4+VIxvZIKgYydECvLfVRwq2MJXr3y5SxsFVA1GpH0kfHj0hoXjy5PINp3GJQReIlvReTd OmKzv5fejYkixYbEmJcn/TMilZvcevMrgBTOybnVAoC37xDEochnf9GmoofpS5HnSuGFucNn+Wqv REeGPKDeGDFyQHtGxv4vjsFqoJSiqWtQUemnQhuTeeZoPUbxDXU6sR77LDz/S3mmTDOmCPC8IFn1 /J+8HVQi1UJLew7unH7VVMbsIzhJs08qaebBl5uWcW2qElDlKIKShgCMmp1DhkmlVaUFoWeomP6R DYL9GXnrbQ81rcOFipoZd/MYhO0F7TtLufsHBJ2t3KOwTYfLwXkF7NCwU7Sb/ABG+WcVFIW47I9s qwtU3BXWIy2bp19c3bqCc4HX6+V847yKXSa5k6ZMy9KaraKlFtymY/fmDGwEhprS2DPM0VIl0qg7 yU0usq5cMV5Y9uREDDb3TFT1j+8HvvA0Ghm9dnhzYc9OAl44HtGp1pVaRFq/FL8Q4mG7fdeY8cSv Yv9Eq4DU8xhTmGJfJa5lM6MgIL0Xc9Pkni9cetDt8+WTRgcNZqcfFYIF0+M99NEvfuoboHNBTcXJ qWc= =qKXa -----END PGP SIGNATURE----- --XeS7eJ5JPg7IwjZ7mWHplNVbGBiq1dAM5--