From: Lucas De Marchi <lucas.demarchi@intel.com>
Date: Fri, 26 Jul 2024 06:43:35 +0000 (-0700)
Subject: drm/xe/rtp: Fix off-by-one when processing rules
X-Git-Tag: configfs-6.13-2024-11-19~386^2~25^2~11
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=fd6797ec50c5;p=users%2Fhch%2Fconfigfs.git

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

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>
---

diff --git a/drivers/gpu/drm/xe/xe_rtp.c b/drivers/gpu/drm/xe/xe_rtp.c
index 02e28274282f..5efe83cc82ab 100644
--- a/drivers/gpu/drm/xe/xe_rtp.c
+++ b/drivers/gpu/drm/xe/xe_rtp.c
@@ -231,7 +231,7 @@ 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);
 }
 
 /**