[PATCH v3 01/23] drm: add vblank hooks to struct drm_crtc_funcs
Andrzej Hajda
a.hajda at samsung.com
Tue Feb 7 10:38:08 UTC 2017
On 07.02.2017 10:16, Shawn Guo wrote:
> From: Shawn Guo <shawn.guo at linaro.org>
>
> The vblank is mostly CRTC specific and implemented as part of CRTC
> driver. Let's keep the vblank hooks struct drm_driver for legacy
> drivers, and add corresponding hooks in struct drm_crtc_funcs. These
> hooks take struct drm_crtc pointer as argument, and will be called by
> core vblank handling code for DRIVER_MODESET drivers.
>
> The new hooks get plugged into core by adding wrapper functions for
> vblank handling code. The .get_vblank_counter hook is effectively
> optional, as we provide drm_vblank_no_hw_counter() as the default
> fallback in the wrapper function.
>
> Signed-off-by: Shawn Guo <shawn.guo at linaro.org>
Every time I have lurked into vblank code I was wondering why it is not
a part of crtc, thanks for clearing it up.
Small comment below, anyway:
Reviewed-by: Andrzej Hajda <a.hajda at samsung.com>
> ---
> drivers/gpu/drm/drm_irq.c | 53 +++++++++++++++++++++++++++++++++++++++++------
> include/drm/drm_crtc.h | 44 +++++++++++++++++++++++++++++++++++++++
> include/drm/drm_drv.h | 9 ++++++++
> 3 files changed, 100 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
> index e06cf11ebb4a..646b3e57b9ad 100644
> --- a/drivers/gpu/drm/drm_irq.c
> +++ b/drivers/gpu/drm/drm_irq.c
> @@ -89,6 +89,21 @@ static void store_vblank(struct drm_device *dev, unsigned int pipe,
> write_sequnlock(&vblank->seqlock);
> }
>
> +static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe)
> +{
> + if (drm_core_check_feature(dev, DRIVER_MODESET)) {
> + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
> +
> + if (crtc->funcs->get_vblank_counter)
> + return crtc->funcs->get_vblank_counter(crtc);
> + }
> +
> + if (dev->driver->get_vblank_counter)
> + return dev->driver->get_vblank_counter(dev, pipe);
After converting all modeset drivers dev->driver->get_vblank_counter
could be called only for non-modeset drivers, ie 'else' can be put
before last if, the same for two other callbacks.
Regards
Andrzej
> +
> + return drm_vblank_no_hw_counter(dev, pipe);
> +}
> +
> /*
> * Reset the stored timestamp for the current vblank count to correspond
> * to the last vblank occurred.
> @@ -112,9 +127,9 @@ static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe
> * when drm_vblank_enable() applies the diff
> */
> do {
> - cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
> + cur_vblank = __get_vblank_counter(dev, pipe);
> rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, 0);
> - } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
> + } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
>
> /*
> * Only reinitialize corresponding vblank timestamp if high-precision query
> @@ -168,9 +183,9 @@ static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe,
> * corresponding vblank timestamp.
> */
> do {
> - cur_vblank = dev->driver->get_vblank_counter(dev, pipe);
> + cur_vblank = __get_vblank_counter(dev, pipe);
> rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, flags);
> - } while (cur_vblank != dev->driver->get_vblank_counter(dev, pipe) && --count > 0);
> + } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0);
>
> if (dev->max_vblank_count != 0) {
> /* trust the hw counter when it's around */
> @@ -275,6 +290,20 @@ u32 drm_accurate_vblank_count(struct drm_crtc *crtc)
> }
> EXPORT_SYMBOL(drm_accurate_vblank_count);
>
> +static void __disable_vblank(struct drm_device *dev, unsigned int pipe)
> +{
> + if (drm_core_check_feature(dev, DRIVER_MODESET)) {
> + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
> +
> + if (crtc->funcs->disable_vblank) {
> + crtc->funcs->disable_vblank(crtc);
> + return;
> + }
> + }
> +
> + dev->driver->disable_vblank(dev, pipe);
> +}
> +
> /*
> * Disable vblank irq's on crtc, make sure that last vblank count
> * of hardware and corresponding consistent software vblank counter
> @@ -298,7 +327,7 @@ static void vblank_disable_and_save(struct drm_device *dev, unsigned int pipe)
> * hardware potentially runtime suspended.
> */
> if (vblank->enabled) {
> - dev->driver->disable_vblank(dev, pipe);
> + __disable_vblank(dev, pipe);
> vblank->enabled = false;
> }
>
> @@ -1027,6 +1056,18 @@ void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
> }
> EXPORT_SYMBOL(drm_crtc_send_vblank_event);
>
> +static int __enable_vblank(struct drm_device *dev, unsigned int pipe)
> +{
> + if (drm_core_check_feature(dev, DRIVER_MODESET)) {
> + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe);
> +
> + if (crtc->funcs->enable_vblank)
> + return crtc->funcs->enable_vblank(crtc);
> + }
> +
> + return dev->driver->enable_vblank(dev, pipe);
> +}
> +
> /**
> * drm_vblank_enable - enable the vblank interrupt on a CRTC
> * @dev: DRM device
> @@ -1052,7 +1093,7 @@ static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe)
> * timestamps. Filtercode in drm_handle_vblank() will
> * prevent double-accounting of same vblank interval.
> */
> - ret = dev->driver->enable_vblank(dev, pipe);
> + ret = __enable_vblank(dev, pipe);
> DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret);
> if (ret)
> atomic_dec(&vblank->refcount);
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 8f0b195e4a59..4323acefa596 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -601,6 +601,50 @@ struct drm_crtc_funcs {
> */
> void (*atomic_print_state)(struct drm_printer *p,
> const struct drm_crtc_state *state);
> +
> + /**
> + * @get_vblank_counter:
> + *
> + * Driver callback for fetching a raw hardware vblank counter for the
> + * CRTC. It's meant to be used by new drivers as the replacement of
> + * &drm_driver.get_vblank_counter hook.
> + *
> + * This callback is optional. If a device doesn't have a hardware
> + * counter, the driver can simply leave the hook as NULL. The DRM core
> + * will account for missed vblank events while interrupts where disabled
> + * based on system timestamps.
> + *
> + * Wraparound handling and loss of events due to modesetting is dealt
> + * with in the DRM core code, as long as drivers call
> + * drm_crtc_vblank_off() and drm_crtc_vblank_on() when disabling or
> + * enabling a CRTC.
> + *
> + * Returns:
> + *
> + * Raw vblank counter value.
> + */
> + u32 (*get_vblank_counter)(struct drm_crtc *crtc);
> +
> + /**
> + * @enable_vblank:
> + *
> + * Enable vblank interrupts for the CRTC. It's meant to be used by
> + * new drivers as the replacement of &drm_driver.enable_vblank hook.
> + *
> + * Returns:
> + *
> + * Zero on success, appropriate errno if the vblank interrupt cannot
> + * be enabled.
> + */
> + int (*enable_vblank)(struct drm_crtc *crtc);
> +
> + /**
> + * @disable_vblank:
> + *
> + * Disable vblank interrupts for the CRTC. It's meant to be used by
> + * new drivers as the replacement of &drm_driver.disable_vblank hook.
> + */
> + void (*disable_vblank)(struct drm_crtc *crtc);
> };
>
> /**
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index f2c0040ddc3a..40ae89106594 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -130,6 +130,9 @@ struct drm_driver {
> * drm_crtc_vblank_off() and drm_crtc_vblank_on() when disabling or
> * enabling a CRTC.
> *
> + * This is deprecated and should not be used by new drivers.
> + * Use &drm_crtc_funcs.get_vblank_counter instead.
> + *
> * Returns:
> *
> * Raw vblank counter value.
> @@ -142,6 +145,9 @@ struct drm_driver {
> * Enable vblank interrupts for the CRTC specified with the pipe
> * argument.
> *
> + * This is deprecated and should not be used by new drivers.
> + * Use &drm_crtc_funcs.enable_vblank instead.
> + *
> * Returns:
> *
> * Zero on success, appropriate errno if the given @crtc's vblank
> @@ -154,6 +160,9 @@ struct drm_driver {
> *
> * Disable vblank interrupts for the CRTC specified with the pipe
> * argument.
> + *
> + * This is deprecated and should not be used by new drivers.
> + * Use &drm_crtc_funcs.disable_vblank instead.
> */
> void (*disable_vblank) (struct drm_device *dev, unsigned int pipe);
>
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