lkml.org 
[lkml]   [2021]   [Dec]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] drm/dp: Actually read Adjust Request Post Cursor2 register
Date
The link_status array was not large enough to read the Adjust Request
Post Cursor2 register. Adjust the size to include it. Found with a
-Warray-bounds build:

drivers/gpu/drm/drm_dp_helper.c: In function 'drm_dp_get_adjust_request_post_cursor':
drivers/gpu/drm/drm_dp_helper.c:59:27: error: array subscript 10 is outside array bounds of 'const u8[6]' {aka 'const unsigned char[6]'} [-Werror=array-bounds]
59 | return link_status[r - DP_LANE0_1_STATUS];
| ~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
drivers/gpu/drm/drm_dp_helper.c:147:51: note: while referencing 'link_status'
147 | u8 drm_dp_get_adjust_request_post_cursor(const u8 link_status[DP_LINK_STATUS_SIZE],
| ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fixes: 79465e0ffeb9 ("drm/dp: Add helper to get post-cursor adjustments")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
include/drm/drm_dp_helper.h | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h
index 472dac376284..277643d2fe2c 100644
--- a/include/drm/drm_dp_helper.h
+++ b/include/drm/drm_dp_helper.h
@@ -1517,7 +1517,15 @@ enum drm_dp_phy {
#define DP_MST_LOGICAL_PORT_0 8

#define DP_LINK_CONSTANT_N_VALUE 0x8000
-#define DP_LINK_STATUS_SIZE 6
+/*
+ * DPCD registers in link_status:
+ * Link Status: 0x202 through 0x204
+ * Sink Status: 0x205
+ * Adjust Request: 0x206 through 0x207
+ * Training Score: 0x208 through 0x20b
+ * AR Post Cursor2: 0x20c
+ */
+#define DP_LINK_STATUS_SIZE 11
bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
int lane_count);
bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE],
--
2.30.2
\
 
 \ /
  Last update: 2021-12-03 09:44    [W:0.120 / U:0.120 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site