Re: [PATCH] drm/i915: Hold CRTC lock whilst freezing the planes

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Thu, 22 May 2014 09:44:40 +0100
Chris Wilson <chris@chris-wilson.co.uk> wrote:

> Daniel keeps on ramping up the warning level of the DRM and our display
> core to make it complain whenever the locking rules are not followed.
> This caught
> 
> commit 24576d23976746cb52e7700c4cadbf4bc1bc3472
> Author: Jesse Barnes <jbarnes@virtuousgeek.org>
> Date:   Tue Mar 26 09:25:45 2013 -0700
> 
>     drm/i915: enable VT switchless resume v3
> 
> introducing an unlocked access to the CRTC whilst disabling it for
> suspend.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78114
> Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
> Cc: Jesse Barnes <jbarnes@virtuousgeek.org>
> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> ---
>  drivers/gpu/drm/i915/i915_drv.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index 591762c26af4..8450569ff42c 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -532,8 +532,11 @@ static int i915_drm_freeze(struct drm_device *dev)
>  		 * for _thaw.
>  		 */
>  		mutex_lock(&dev->mode_config.mutex);
> -		for_each_crtc(dev, crtc)
> +		for_each_crtc(dev, crtc) {
> +			mutex_lock(&crtc->mutex);
>  			dev_priv->display.crtc_disable(crtc);
> +			mutex_unlock(&crtc->mutex);
> +		}
>  		mutex_unlock(&dev->mode_config.mutex);
>  
>  		intel_modeset_suspend_hw(dev);

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center