[Acked/cmt] [PULL][Vivid SRU] another urgent fix for i915_bpo -- PATCHES

Andy Whitcroft apw at canonical.com
Wed Sep 9 09:31:12 UTC 2015


On Wed, Sep 09, 2015 at 10:20:52AM +0100, Andy Whitcroft wrote:
> On Wed, Sep 09, 2015 at 12:02:27PM +0300, Timo Aaltonen wrote:
> > 
> > 	Hi
> > 
> >   This backport fixes an urgent bug on Skylake, where changing between
> > mirror/extended modes causes a system hang..
> > 
> > 
> > The following changes since commit 48daf2e6d3442eb86a3cb8b912e432fa2a3d7804:
> > 
> >   Linux 3.19.8-ckt6 (2015-09-08 15:48:27 +0100)
> > 
> > are available in the git repository at:
> > 
> >   git://kernel.ubuntu.com/tjaalton/ubuntu-vivid.git i915-bpo
> > 
> > for you to fetch changes up to fca8a268c36f223bc923e6443bf51811133c97cb:
> > 
> >   UBUNTU: SAUCE: i915_bpo: drm/i915: Split atomic wm update to pre and
> > post variants (2015-09-09 11:55:13 +0300)
> > 
> > ----------------------------------------------------------------
> > Ville Syrjälä (1):
> >       UBUNTU: SAUCE: i915_bpo: drm/i915: Split atomic wm update to pre
> > and post variants
> > 
> >  ubuntu/i915/intel_display.c | 15 +++++++++++----
> >  ubuntu/i915/intel_drv.h     |  2 +-
> >  ubuntu/i915/intel_sprite.c  |  2 +-
> >  3 files changed, 13 insertions(+), 6 deletions(-)
> 
> Patches:
> 
> commit fca8a268c36f223bc923e6443bf51811133c97cb
> Author: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Date:   Wed Jun 24 22:00:02 2015 +0300
> 
>     UBUNTU: SAUCE: i915_bpo: drm/i915: Split atomic wm update to pre and post variants
>     
>     BugLink: http://bugs.launchpad.net/bugs/1493746
>     
>     Try to update the watermarks on the right side of the plane update. This
>     is just a temporary hack until we get the proper two part update into
>     place. However in the meantime this might have some chance of at least
>     working.
>     
>     Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
>     Reviewed-by: Clint Taylor <Clinton.A.Taylor at intel.com>
>     Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>     (backported from commit f015c5518879fb3e578caaa63806617468a24045)
>     Signed-off-by: Timo Aaltonen <timo.aaltonen at canonical.com>
> 
> diff --git a/ubuntu/i915/intel_display.c b/ubuntu/i915/intel_display.c
> index 44bc1c9..36e2860 100644
> --- a/ubuntu/i915/intel_display.c
> +++ b/ubuntu/i915/intel_display.c
> @@ -13294,8 +13294,12 @@ intel_check_primary_plane(struct drm_plane *plane,
>  
>  		intel_crtc->atomic.update_fbc = true;
>  
> -		if (intel_wm_need_update(plane, &state->base))
> -			intel_crtc->atomic.update_wm = true;
> +		if (state->visible && !old_state->visible)
> +			intel_crtc->atomic.update_wm_pre = true;
> +		else if (!state->visible && old_state->visible)
> +			intel_crtc->atomic.update_wm_post = true;
> +		else if (intel_wm_need_update(plane, &state->base))
> +			intel_crtc->atomic.update_wm_pre = true;
>  	}
>  
>  	if (INTEL_INFO(dev)->gen >= 9) {
> @@ -13392,7 +13396,7 @@ static void intel_begin_crtc_commit(struct drm_crtc *crtc)
>  	if (intel_crtc->atomic.pre_disable_primary)
>  		intel_pre_disable_primary(crtc);
>  
> -	if (intel_crtc->atomic.update_wm)
> +	if (intel_crtc->atomic.update_wm_pre)
>  		intel_update_watermarks(crtc);
>  
>  	intel_runtime_pm_get(dev_priv);
> @@ -13422,6 +13426,9 @@ static void intel_finish_crtc_commit(struct drm_crtc *crtc)
>  
>  	intel_frontbuffer_flip(dev, intel_crtc->atomic.fb_bits);
>  
> +	if (intel_crtc->atomic.update_wm_post)
> +	        intel_update_watermarks(crtc);
> +
>  	if (intel_crtc->atomic.update_fbc) {
>  		mutex_lock(&dev->struct_mutex);
>  		intel_fbc_update(dev);
> @@ -13593,7 +13600,7 @@ intel_check_cursor_plane(struct drm_plane *plane,
>  finish:
>  	if (intel_crtc->active) {
>  		if (plane->state->crtc_w != state->base.crtc_w)
> -			intel_crtc->atomic.update_wm = true;
> +			intel_crtc->atomic.update_wm_post = true;
>  
>  		intel_crtc->atomic.fb_bits |=
>  			INTEL_FRONTBUFFER_CURSOR(intel_crtc->pipe);
> diff --git a/ubuntu/i915/intel_drv.h b/ubuntu/i915/intel_drv.h
> index 9983ba7..76252a88 100644
> --- a/ubuntu/i915/intel_drv.h
> +++ b/ubuntu/i915/intel_drv.h
> @@ -487,7 +487,7 @@ struct intel_crtc_atomic_commit {
>  	bool disable_fbc;
>  	bool disable_ips;
>  	bool pre_disable_primary;
> -	bool update_wm;
> +	bool update_wm_pre, update_wm_post;
>  	unsigned disabled_planes;
>  
>  	/* Sleepable operations to perform after commit */
> diff --git a/ubuntu/i915/intel_sprite.c b/ubuntu/i915/intel_sprite.c
> index 8193a35..15379f9 100644
> --- a/ubuntu/i915/intel_sprite.c
> +++ b/ubuntu/i915/intel_sprite.c
> @@ -927,7 +927,7 @@ finish:
>  			INTEL_FRONTBUFFER_SPRITE(intel_crtc->pipe);
>  
>  		if (intel_wm_need_update(plane, &state->base))
> -			intel_crtc->atomic.update_wm = true;
> +			intel_crtc->atomic.update_wm_pre = true;
>  
>  		if (!state->visible) {
>  			/*

As the description does not tell us what the criteria for fix _is_ it is
impossible to audit that this actually does what was intended (they
did not bother to tell us).  I guess it only changes when whatermarks
are handled so thats something.  It only applies to the limited backport
version of the driver.  I guess a grudging:

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw




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