drm/xe/rtp: Fix off-by-one when processing rules

[ Upstream commit ae02c7b7fea3e034fbd724c21d88406f71ccc2f8 ]

Gustavo noticed an odd "+ 2" in rtp_mark_active() while processing
rtp rules and pointed that it should be "+ 1". In fact, while processing
entries without actions (OOB workarounds), if the WA is activated and
has OR rules, it will also inadvertently activate the very next
workaround.

Test in a LNL B0 platform by moving 18024947630 on top of 16020292621,
makes the latter become active:

	$ cat /sys/kernel/debug/dri/0/gt0/workarounds
	...
	OOB Workarounds
		18024947630
		16020292621
		14018094691
		16022287689
		13011645652
		22019338487_display

In future a kunit test will be added to cover the rtp checks for entries
without actions.

Fixes: fe19328b900c ("drm/xe/rtp: Add support for entries with no action")
Cc: Gustavo Sousa <gustavo.sousa@intel.com>
Reviewed-by: Gustavo Sousa <gustavo.sousa@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240726064337.797576-6-lucas.demarchi@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
(cherry picked from commit fd6797ec50c561f085bc94e3ee26f484a52af79e)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/xe/xe_rtp.c b/drivers/gpu/drm/xe/xe_rtp.c
index fb44cc7521d8c1e0133c2730f1f1d52d05cc2185..10326bd1bfa3bf1d9c9567d8ae40abcff54dff5d 100644 (file)
--- a/drivers/gpu/drm/xe/xe_rtp.c
+++ b/drivers/gpu/drm/xe/xe_rtp.c
@@ -200,7 +200,7 @@ static void rtp_mark_active(struct xe_device *xe,
        if (first == last)
                bitmap_set(ctx->active_entries, first, 1);
        else
-               bitmap_set(ctx->active_entries, first, last - first + 2);
+               bitmap_set(ctx->active_entries, first, last - first + 1);
 }
 
 /**