[Intel-gfx] [PATCH] drm/i915/debugfs: Increment return value of gt.next_seqno

[Joonas Lahtinen]

On to, 2016-11-24 at 09:47 +0000, Chris Wilson wrote:
> The i915_next_seqno read value is to be the next seqno used by the
> kernel. However, in the conversion to atomics ops for gt.next_seqno, in
> commit 28176ef4cfa5 ("drm/i915: Reserve space in the global seqno during
> request allocation"), this was changed from a post-increment to a
> pre-increment. This increment was missed from the value reported by
> debugfs, so in effect it was reporting the current seqno (last
> assigned), not the next seqno.
> 
> Fixes: 28176ef4cfa5 ("drm/i915: Reserve space in the global seqno during request allocation")
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=81209
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

<SNIP>

> @@ -1026,7 +1026,7 @@ i915_next_seqno_get(void *data, u64 *val)
>  {
>  	struct drm_i915_private *dev_priv = data;
>  
> -	*val = atomic_read(&dev_priv->gt.global_timeline.next_seqno);
> +	*val = 1 + atomic_read(&dev_priv->gt.global_timeline.next_seqno);

The variable name really should be last_seqno or so...

But as a hotfix;

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

Regards, joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation