| Message ID | 20210624072916.27703-5-tzimmermann@suse.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Deprecate struct drm_device.irq_enabled | expand |
On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> 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 <tzimmermann@suse.de> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> > Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> > --- > 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);
Hi Am 24.06.21 um 10:06 schrieb Jani Nikula: > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> 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 <tzimmermann@suse.de> >> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> >> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> >> --- >> 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. I don't like them either. I guess I'll go with suggestion 2. Thanks for the feedback. Best regards Thomas > > 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); >
Hi Am 24.06.21 um 10:06 schrieb Jani Nikula: > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> 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 <tzimmermann@suse.de> >> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> >> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> >> --- >> 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); >
On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: > Hi > > Am 24.06.21 um 10:06 schrieb Jani Nikula: >> On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: >>> 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. It's definitely better than the original, but it's unclear to me why you'd prefer this over option 2) below. I guess the only reason I can think of is emphasizing the conditional compilation. However, IS_ENABLED() is widely used in this manner specifically to avoid inline #if, and the compiler optimizes it away. BR, Jani. > > 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); >>
Hi Am 24.06.21 um 10:51 schrieb Jani Nikula: > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: >> Hi >> >> Am 24.06.21 um 10:06 schrieb Jani Nikula: >>> On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: >>>> 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. > > It's definitely better than the original, but it's unclear to me why > you'd prefer this over option 2) below. I guess the only reason I can > think of is emphasizing the conditional compilation. However, > IS_ENABLED() is widely used in this manner specifically to avoid inline > #if, and the compiler optimizes it away. It's simply more readable to me as the condition is simpler. But option 2 is also ok. Best regards Thomas > > BR, > Jani. > > >> >> 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); >>> >
On Thu, Jun 24, 2021 at 11:07:57AM +0200, Thomas Zimmermann wrote: > Hi > > Am 24.06.21 um 10:51 schrieb Jani Nikula: > > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > Hi > > > > > > Am 24.06.21 um 10:06 schrieb Jani Nikula: > > > > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > > > 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. > > > > It's definitely better than the original, but it's unclear to me why > > you'd prefer this over option 2) below. I guess the only reason I can > > think of is emphasizing the conditional compilation. However, > > IS_ENABLED() is widely used in this manner specifically to avoid inline > > #if, and the compiler optimizes it away. > > It's simply more readable to me as the condition is simpler. But option 2 is > also ok. Either option looks good to me. Reviewed-by: Liviu Dudau <liviu.dudau@arm.com> Thanks for doing that! Liviu > > Best regards > Thomas > > > > > BR, > > Jani. > > > > > > > > > > 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 >
On Thu, Jun 24, 2021 at 11:07:57AM +0200, Thomas Zimmermann wrote: > Hi > > Am 24.06.21 um 10:51 schrieb Jani Nikula: > > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > Hi > > > > > > Am 24.06.21 um 10:06 schrieb Jani Nikula: > > > > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: > > > > > 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. > > > > It's definitely better than the original, but it's unclear to me why > > you'd prefer this over option 2) below. I guess the only reason I can > > think of is emphasizing the conditional compilation. However, > > IS_ENABLED() is widely used in this manner specifically to avoid inline > > #if, and the compiler optimizes it away. > > It's simply more readable to me as the condition is simpler. But option 2 is > also ok. Perhaps do something like this, then: if (IS_ENABLED(CONFIG_DRM_LEGACY)) { if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) return dev->irq_enabled; } return drm_dev_has_vblank(dev); That's about just as readable as the variant involving the preprocessor but has all the benefits of not using the preprocessor. Thierry
On Thu, 24 Jun 2021, Thierry Reding <thierry.reding@gmail.com> wrote: > On Thu, Jun 24, 2021 at 11:07:57AM +0200, Thomas Zimmermann wrote: >> Hi >> >> Am 24.06.21 um 10:51 schrieb Jani Nikula: >> > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: >> > > Hi >> > > >> > > Am 24.06.21 um 10:06 schrieb Jani Nikula: >> > > > On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: >> > > > > 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. >> > >> > It's definitely better than the original, but it's unclear to me why >> > you'd prefer this over option 2) below. I guess the only reason I can >> > think of is emphasizing the conditional compilation. However, >> > IS_ENABLED() is widely used in this manner specifically to avoid inline >> > #if, and the compiler optimizes it away. >> >> It's simply more readable to me as the condition is simpler. But option 2 is >> also ok. > > Perhaps do something like this, then: > > if (IS_ENABLED(CONFIG_DRM_LEGACY)) { > if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) > return dev->irq_enabled; > } > > return drm_dev_has_vblank(dev); > > That's about just as readable as the variant involving the preprocessor > but has all the benefits of not using the preprocessor. Looks like a winner to me. :) BR, Jani.
Hi Am 24.06.21 um 14:36 schrieb Jani Nikula: > On Thu, 24 Jun 2021, Thierry Reding <thierry.reding@gmail.com> wrote: >> On Thu, Jun 24, 2021 at 11:07:57AM +0200, Thomas Zimmermann wrote: >>> Hi >>> >>> Am 24.06.21 um 10:51 schrieb Jani Nikula: >>>> On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: >>>>> Hi >>>>> >>>>> Am 24.06.21 um 10:06 schrieb Jani Nikula: >>>>>> On Thu, 24 Jun 2021, Thomas Zimmermann <tzimmermann@suse.de> wrote: >>>>>>> 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. >>>> >>>> It's definitely better than the original, but it's unclear to me why >>>> you'd prefer this over option 2) below. I guess the only reason I can >>>> think of is emphasizing the conditional compilation. However, >>>> IS_ENABLED() is widely used in this manner specifically to avoid inline >>>> #if, and the compiler optimizes it away. >>> >>> It's simply more readable to me as the condition is simpler. But option 2 is >>> also ok. >> >> Perhaps do something like this, then: >> >> if (IS_ENABLED(CONFIG_DRM_LEGACY)) { >> if (unlikely(drm_core_check_feature(dev, DRIVER_LEGACY))) >> return dev->irq_enabled; >> } >> >> return drm_dev_has_vblank(dev); >> >> That's about just as readable as the variant involving the preprocessor >> but has all the benefits of not using the preprocessor. > > Looks like a winner to me. :) That's the most readable. But I just remembered that irq_enabled will likely become legacy-only in the device structure. We'll need an ifdef variant then. :/ Best regards Thomas > > BR, > Jani. > >
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; + } 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);