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

[Chris Wilson]

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>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 4cad5bf116b5..7b0fcd7461ea 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -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);
 	return 0;
 }
 
-- 
2.10.2