[Intel-gfx] [PATCH 1/4] drm/i915: Stop allowing the device to be unwedged

[Chris Wilson]

On Wed, Mar 08, 2017 at 11:40:07AM +0000, Chris Wilson wrote:
> Since commit 821ed7df6e2a ("drm/i915: Update reset path to fix
> incomplete requests"), setting the device as wedged is permanent as we
> cannot recover the engine->submit_request. Stop clearing the I915_WEDGED
> status to prevent userspace can getting itself in a muddle.
> 
> To fix this correctly, we need to stop overriding engine->submit_request
> for the inflight requests and instead need to track the errors in
> flight. In the meantime, let's start with the correctness fix.
> 
> Fixes: 821ed7df6e2a ("drm/i915: Update reset path to fix incomplete requests")
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Mika Kuoppala <mika.kuoppala at intel.com>
> Cc: <stable at vger.kernel.org> # v4.9+
> ---
>  drivers/gpu/drm/i915/i915_drv.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> index b1e9027a4f80..1c4f0a21eb22 100644
> --- a/drivers/gpu/drm/i915/i915_drv.c
> +++ b/drivers/gpu/drm/i915/i915_drv.c
> @@ -1824,8 +1824,11 @@ void i915_reset(struct drm_i915_private *dev_priv)
>  	if (!test_and_clear_bit(I915_RESET_IN_PROGRESS, &error->flags))
>  		return;
>  
> -	/* Clear any previous failed attempts at recovery. Time to try again. */
> -	__clear_bit(I915_WEDGED, &error->flags);
> +	if (test_bit(I915_WEDGED, &error->flags)) {
> +		wake_up_bit(&error->flags, I915_RESET_IN_PROGRESS);
> +		goto out;

Double wakeup; just goto out;
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre