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 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: 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 > > 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); > -- Thomas Zimmermann Graphics Driver Developer SUSE Software Solutions Germany GmbH Maxfeldstr. 5, 90409 Nürnberg, Germany (HRB 36809, AG Nürnberg) Geschäftsführer: Felix Imendörffer