[PATCH] drm/edid: Fix uninitialized variable in drm_cvt_modes()

From: Lyude Paul
Date: Thu Oct 22 2020 - 12:55:03 EST


Noticed this when trying to compile with -Wall on a kernel fork. We potentially
don't set width here, which causes the compiler to complain about width
potentially being uninitialized in drm_cvt_modes(). So, let's fix that.

Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>

Cc: <stable@xxxxxxxxxxxxxxx> # v5.9+
Fixes: 3f649ab728cd ("treewide: Remove uninitialized_var() usage")
Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
---
drivers/gpu/drm/drm_edid.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index 631125b46e04..2da158ffed8e 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -3094,6 +3094,7 @@ static int drm_cvt_modes(struct drm_connector *connector,

for (i = 0; i < 4; i++) {
int width, height;
+ u8 cvt_aspect_ratio;

cvt = &(timing->data.other_data.data.cvt[i]);

@@ -3101,7 +3102,8 @@ static int drm_cvt_modes(struct drm_connector *connector,
continue;

height = (cvt->code[0] + ((cvt->code[1] & 0xf0) << 4) + 1) * 2;
- switch (cvt->code[1] & 0x0c) {
+ cvt_aspect_ratio = cvt->code[1] & 0x0c;
+ switch (cvt_aspect_ratio) {
case 0x00:
width = height * 4 / 3;
break;
@@ -3114,6 +3116,10 @@ static int drm_cvt_modes(struct drm_connector *connector,
case 0x0c:
width = height * 15 / 9;
break;
+ default:
+ drm_dbg_kms(dev, "[CONNECTOR:%d:%s] unknown CVT aspect ratio %x\n",
+ connector->base.id, connector->name, cvt_aspect_ratio);
+ continue;
}

for (j = 1; j < 5; j++) {
--
2.26.2