[PATCH 5.9 327/391] drm/amd/display: Fix kernel panic by dal_gpio_open() error

From: Greg Kroah-Hartman
Date: Tue Nov 03 2020 - 16:48:20 EST


From: Takashi Iwai <tiwai@xxxxxxx>

commit 920bb38c518408fa2600eaefa0af9e82cf48f166 upstream.

Currently both error code paths handled in dal_gpio_open_ex() issues
ASSERT_CRITICAL(), and this leads to a kernel panic unnecessarily if
CONFIG_KGDB is enabled. Since basically both are non-critical errors
and can be recovered, drop those assert calls and use a safer one,
BREAK_TO_DEBUGGER(), for allowing the debugging, instead.

BugLink: https://bugzilla.opensuse.org/show_bug.cgi?id=1177973
Cc: <stable@xxxxxxxxxxxxxxx>
Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c
+++ b/drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c
@@ -63,13 +63,13 @@ enum gpio_result dal_gpio_open_ex(
enum gpio_mode mode)
{
if (gpio->pin) {
- ASSERT_CRITICAL(false);
+ BREAK_TO_DEBUGGER();
return GPIO_RESULT_ALREADY_OPENED;
}

// No action if allocation failed during gpio construct
if (!gpio->hw_container.ddc) {
- ASSERT_CRITICAL(false);
+ BREAK_TO_DEBUGGER();
return GPIO_RESULT_NON_SPECIFIC_ERROR;
}
gpio->mode = mode;