From: Ville Syrjälä ville.syrjala@linux.intel.com
Add a flag to drm_device which will cause the vblank code to bypass the disable timer and always disable the vblank interrupt immediately when the last reference is dropped.
v2: Add some notes about the flag to the kernel doc
Reviewed-by: Matt Roper matthew.d.roper@intel.com Reviewed-by: Daniel Vetter daniel.vetter@ffwll.ch Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com --- Documentation/DocBook/drm.tmpl | 6 ++++++ drivers/gpu/drm/drm_irq.c | 2 +- include/drm/drmP.h | 10 ++++++++++ 3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index 1cbe2a0..3ec4b2b 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -3387,6 +3387,12 @@ void (*disable_vblank) (struct drm_device *dev, int crtc);</synopsis> module parameter or the <varname>drm_vblank_offdelay</varname> global variable and expressed in milliseconds. Its default value is 5000 ms. Zero means never disable, and a negative value means disable immediately. + Drivers may override the behaviour by setting the + <structname>drm_device</structname> + <structfield>vblank_disable_immediate</structfield> flag, which when set + causes vblank interrupts to be disabled immediately regardless of the + drm_vblank_offdelay value. The flag should only be set if there's a + properly working hardware vblank counter present. </para> <para> When a vertical blanking interrupt occurs drivers only need to call the diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c index 99145c4..8dbcc3f 100644 --- a/drivers/gpu/drm/drm_irq.c +++ b/drivers/gpu/drm/drm_irq.c @@ -994,7 +994,7 @@ void drm_vblank_put(struct drm_device *dev, int crtc)
/* Last user schedules interrupt disable */ if (atomic_dec_and_test(&vblank->refcount)) { - if (drm_vblank_offdelay < 0) + if (dev->vblank_disable_immediate || drm_vblank_offdelay < 0) vblank_disable_fn((unsigned long)vblank); else if (drm_vblank_offdelay > 0) mod_timer(&vblank->disable_timer, diff --git a/include/drm/drmP.h b/include/drm/drmP.h index cdcc60b..3c22c35 100644 --- a/include/drm/drmP.h +++ b/include/drm/drmP.h @@ -1077,6 +1077,16 @@ struct drm_device { */ bool vblank_disable_allowed;
+ /* + * If true, vblank interrupt will be disabled immediately when the + * refcount drops to zero, as opposed to via the vblank disable + * timer. + * This can be set to true it the hardware has a working vblank + * counter and the driver uses drm_vblank_on() and drm_vblank_off() + * appropriately. + */ + bool vblank_disable_immediate; + /* array of size num_crtcs */ struct drm_vblank_crtc *vblank;