* [PATCH 1/3] drm/amd/display: Fix kernel panic by dal_gpio_open() error
2020-10-23 7:46 [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint Takashi Iwai
@ 2020-10-23 7:46 ` Takashi Iwai
2020-10-23 7:46 ` [PATCH 2/3] drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally Takashi Iwai
` (2 subsequent siblings)
3 siblings, 0 replies; 8+ messages in thread
From: Takashi Iwai @ 2020-10-23 7:46 UTC (permalink / raw)
To: dri-devel; +Cc: amd-gfx, linux-kernel
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@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c b/drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c
index f67c18375bfd..dac427b68fd7 100644
--- 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;
--
2.16.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 2/3] drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally
2020-10-23 7:46 [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint Takashi Iwai
2020-10-23 7:46 ` [PATCH 1/3] drm/amd/display: Fix kernel panic by dal_gpio_open() error Takashi Iwai
@ 2020-10-23 7:46 ` Takashi Iwai
2020-10-23 7:46 ` [PATCH 3/3] drm/amd/display: Clean up debug macros Takashi Iwai
2020-10-23 23:16 ` [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint Luben Tuikov
3 siblings, 0 replies; 8+ messages in thread
From: Takashi Iwai @ 2020-10-23 7:46 UTC (permalink / raw)
To: dri-devel; +Cc: amd-gfx, linux-kernel
ASSERT_CRITICAL() invokes kgdb_breakpoint() whenever either
CONFIG_KGDB or CONFIG_HAVE_KGDB is set. This, however, may lead to a
kernel panic when no kdb stuff is attached, since the
kgdb_breakpoint() call issues INT3. It's nothing but a surprise for
normal end-users.
For avoiding the pitfall, make the kgdb_breakpoint() call only when
CONFIG_DEBUG_KERNEL_DC is set.
https://bugzilla.opensuse.org/show_bug.cgi?id=1177973
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/amd/display/dc/os_types.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h
index 330acaaed79a..32758b245754 100644
--- a/drivers/gpu/drm/amd/display/dc/os_types.h
+++ b/drivers/gpu/drm/amd/display/dc/os_types.h
@@ -94,7 +94,7 @@
* general debug capabilities
*
*/
-#if defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB)
+#if defined(CONFIG_DEBUG_KERNEL_DC) && (defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB))
#define ASSERT_CRITICAL(expr) do { \
if (WARN_ON(!(expr))) { \
kgdb_breakpoint(); \
--
2.16.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* [PATCH 3/3] drm/amd/display: Clean up debug macros
2020-10-23 7:46 [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint Takashi Iwai
2020-10-23 7:46 ` [PATCH 1/3] drm/amd/display: Fix kernel panic by dal_gpio_open() error Takashi Iwai
2020-10-23 7:46 ` [PATCH 2/3] drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally Takashi Iwai
@ 2020-10-23 7:46 ` Takashi Iwai
2020-10-23 23:16 ` [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint Luben Tuikov
3 siblings, 0 replies; 8+ messages in thread
From: Takashi Iwai @ 2020-10-23 7:46 UTC (permalink / raw)
To: dri-devel; +Cc: amd-gfx, linux-kernel
This patch simplifies the ASSERT*() and BREAK_TO_DEBUGGER() macros:
- Move the dependency check of CONFIG_KGDB into Kconfig
- Unify the kgdb_breakpoint() call
- Drop the non-existing CONFIG_HAVE_KGDB
Also align the behavior of ASSERT() macro in both cases with and
without CONFIG_DEBUG_KERNEL_DC.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
drivers/gpu/drm/amd/display/Kconfig | 1 +
drivers/gpu/drm/amd/display/dc/os_types.h | 33 +++++++++++--------------------
2 files changed, 13 insertions(+), 21 deletions(-)
diff --git a/drivers/gpu/drm/amd/display/Kconfig b/drivers/gpu/drm/amd/display/Kconfig
index f24abf428534..60dfdd432aba 100644
--- a/drivers/gpu/drm/amd/display/Kconfig
+++ b/drivers/gpu/drm/amd/display/Kconfig
@@ -42,6 +42,7 @@ config DRM_AMD_DC_SI
config DEBUG_KERNEL_DC
bool "Enable kgdb break in DC"
depends on DRM_AMD_DC
+ depends on KGDB
help
Choose this option if you want to hit kdgb_break in assert.
diff --git a/drivers/gpu/drm/amd/display/dc/os_types.h b/drivers/gpu/drm/amd/display/dc/os_types.h
index 32758b245754..95cb56929e79 100644
--- a/drivers/gpu/drm/amd/display/dc/os_types.h
+++ b/drivers/gpu/drm/amd/display/dc/os_types.h
@@ -94,36 +94,27 @@
* general debug capabilities
*
*/
-#if defined(CONFIG_DEBUG_KERNEL_DC) && (defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB))
-#define ASSERT_CRITICAL(expr) do { \
- if (WARN_ON(!(expr))) { \
- kgdb_breakpoint(); \
- } \
-} while (0)
+#ifdef CONFIG_DEBUG_KERNEL_DC
+#define dc_breakpoint() kgdb_breakpoint()
#else
-#define ASSERT_CRITICAL(expr) do { \
- if (WARN_ON(!(expr))) { \
- ; \
- } \
-} while (0)
+#define dc_breakpoint() do {} while (0)
#endif
-#if defined(CONFIG_DEBUG_KERNEL_DC)
-#define ASSERT(expr) ASSERT_CRITICAL(expr)
+#define ASSERT_CRITICAL(expr) do { \
+ if (WARN_ON(!(expr))) \
+ dc_breakpoint(); \
+ } while (0)
-#else
-#define ASSERT(expr) WARN_ON_ONCE(!(expr))
-#endif
+#define ASSERT(expr) do { \
+ if (WARN_ON_ONCE(!(expr))) \
+ dc_breakpoint(); \
+ } while (0)
-#if defined(CONFIG_DEBUG_KERNEL_DC) && (defined(CONFIG_HAVE_KGDB) || defined(CONFIG_KGDB))
#define BREAK_TO_DEBUGGER() \
do { \
DRM_DEBUG_DRIVER("%s():%d\n", __func__, __LINE__); \
- kgdb_breakpoint(); \
+ dc_breakpoint(); \
} while (0)
-#else
-#define BREAK_TO_DEBUGGER() DRM_DEBUG_DRIVER("%s():%d\n", __func__, __LINE__)
-#endif
#define DC_ERR(...) do { \
dm_error(__VA_ARGS__); \
--
2.16.4
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint
2020-10-23 7:46 [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint Takashi Iwai
` (2 preceding siblings ...)
2020-10-23 7:46 ` [PATCH 3/3] drm/amd/display: Clean up debug macros Takashi Iwai
@ 2020-10-23 23:16 ` Luben Tuikov
2020-10-26 19:34 ` Alex Deucher
3 siblings, 1 reply; 8+ messages in thread
From: Luben Tuikov @ 2020-10-23 23:16 UTC (permalink / raw)
To: Takashi Iwai, dri-devel; +Cc: linux-kernel, amd-gfx
On 2020-10-23 03:46, Takashi Iwai wrote:
> Hi,
>
> the amdgpu driver's ASSERT_CRITICAL() macro calls the
> kgdb_breakpoing() even if no debug option is set, and this leads to a
> kernel panic on distro kernels. The first two patches are the
> oneliner fixes for those, while the last one is the cleanup of those
> debug macros.
This looks like good work and solid. Hopefully it gets picked up.
Regards,
Luben
>
>
> Takashi
>
> ===
>
> Takashi Iwai (3):
> drm/amd/display: Fix kernel panic by dal_gpio_open() error
> drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally
> drm/amd/display: Clean up debug macros
>
> drivers/gpu/drm/amd/display/Kconfig | 1 +
> drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c | 4 +--
> drivers/gpu/drm/amd/display/dc/os_types.h | 33 +++++++++----------------
> 3 files changed, 15 insertions(+), 23 deletions(-)
>
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint
2020-10-23 23:16 ` [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint Luben Tuikov
@ 2020-10-26 19:34 ` Alex Deucher
2020-10-26 20:22 ` Kazlauskas, Nicholas
0 siblings, 1 reply; 8+ messages in thread
From: Alex Deucher @ 2020-10-26 19:34 UTC (permalink / raw)
To: Luben Tuikov
Cc: Takashi Iwai, Maling list - DRI developers, LKML, amd-gfx list
Yes, looks good to me as well. Series is:
Acked-by: Alex Deucher <alexander.deucher@amd.com>
I'll give the display guys a few more days to look this over, but if
there are no objections, I'll apply them.
Thanks!
Alex
On Fri, Oct 23, 2020 at 7:16 PM Luben Tuikov <luben.tuikov@amd.com> wrote:
>
> On 2020-10-23 03:46, Takashi Iwai wrote:
> > Hi,
> >
> > the amdgpu driver's ASSERT_CRITICAL() macro calls the
> > kgdb_breakpoing() even if no debug option is set, and this leads to a
> > kernel panic on distro kernels. The first two patches are the
> > oneliner fixes for those, while the last one is the cleanup of those
> > debug macros.
>
> This looks like good work and solid. Hopefully it gets picked up.
>
> Regards,
> Luben
>
> >
> >
> > Takashi
> >
> > ===
> >
> > Takashi Iwai (3):
> > drm/amd/display: Fix kernel panic by dal_gpio_open() error
> > drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally
> > drm/amd/display: Clean up debug macros
> >
> > drivers/gpu/drm/amd/display/Kconfig | 1 +
> > drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c | 4 +--
> > drivers/gpu/drm/amd/display/dc/os_types.h | 33 +++++++++----------------
> > 3 files changed, 15 insertions(+), 23 deletions(-)
> >
>
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint
2020-10-26 19:34 ` Alex Deucher
@ 2020-10-26 20:22 ` Kazlauskas, Nicholas
2020-10-26 20:33 ` Alex Deucher
0 siblings, 1 reply; 8+ messages in thread
From: Kazlauskas, Nicholas @ 2020-10-26 20:22 UTC (permalink / raw)
To: Alex Deucher, Luben Tuikov
Cc: Takashi Iwai, amd-gfx list, LKML, Maling list - DRI developers
Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Looks fine to me. Feel free to apply.
Regards,
Nicholas Kazlauskas
On 2020-10-26 3:34 p.m., Alex Deucher wrote:
> Yes, looks good to me as well. Series is:
> Acked-by: Alex Deucher <alexander.deucher@amd.com>
> I'll give the display guys a few more days to look this over, but if
> there are no objections, I'll apply them.
>
> Thanks!
>
> Alex
>
> On Fri, Oct 23, 2020 at 7:16 PM Luben Tuikov <luben.tuikov@amd.com> wrote:
>>
>> On 2020-10-23 03:46, Takashi Iwai wrote:
>>> Hi,
>>>
>>> the amdgpu driver's ASSERT_CRITICAL() macro calls the
>>> kgdb_breakpoing() even if no debug option is set, and this leads to a
>>> kernel panic on distro kernels. The first two patches are the
>>> oneliner fixes for those, while the last one is the cleanup of those
>>> debug macros.
>>
>> This looks like good work and solid. Hopefully it gets picked up.
>>
>> Regards,
>> Luben
>>
>>>
>>>
>>> Takashi
>>>
>>> ===
>>>
>>> Takashi Iwai (3):
>>> drm/amd/display: Fix kernel panic by dal_gpio_open() error
>>> drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally
>>> drm/amd/display: Clean up debug macros
>>>
>>> drivers/gpu/drm/amd/display/Kconfig | 1 +
>>> drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c | 4 +--
>>> drivers/gpu/drm/amd/display/dc/os_types.h | 33 +++++++++----------------
>>> 3 files changed, 15 insertions(+), 23 deletions(-)
>>>
>>
>> _______________________________________________
>> amd-gfx mailing list
>> amd-gfx@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> _______________________________________________
> amd-gfx mailing list
> amd-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 0/3] drm/amd/display: Fix kernel panic by breakpoint
2020-10-26 20:22 ` Kazlauskas, Nicholas
@ 2020-10-26 20:33 ` Alex Deucher
0 siblings, 0 replies; 8+ messages in thread
From: Alex Deucher @ 2020-10-26 20:33 UTC (permalink / raw)
To: Kazlauskas, Nicholas
Cc: Luben Tuikov, Takashi Iwai, amd-gfx list, LKML,
Maling list - DRI developers
Applied. Thanks!
Alex
On Mon, Oct 26, 2020 at 4:22 PM Kazlauskas, Nicholas
<nicholas.kazlauskas@amd.com> wrote:
>
> Reviewed-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
>
> Looks fine to me. Feel free to apply.
>
> Regards,
> Nicholas Kazlauskas
>
> On 2020-10-26 3:34 p.m., Alex Deucher wrote:
> > Yes, looks good to me as well. Series is:
> > Acked-by: Alex Deucher <alexander.deucher@amd.com>
> > I'll give the display guys a few more days to look this over, but if
> > there are no objections, I'll apply them.
> >
> > Thanks!
> >
> > Alex
> >
> > On Fri, Oct 23, 2020 at 7:16 PM Luben Tuikov <luben.tuikov@amd.com> wrote:
> >>
> >> On 2020-10-23 03:46, Takashi Iwai wrote:
> >>> Hi,
> >>>
> >>> the amdgpu driver's ASSERT_CRITICAL() macro calls the
> >>> kgdb_breakpoing() even if no debug option is set, and this leads to a
> >>> kernel panic on distro kernels. The first two patches are the
> >>> oneliner fixes for those, while the last one is the cleanup of those
> >>> debug macros.
> >>
> >> This looks like good work and solid. Hopefully it gets picked up.
> >>
> >> Regards,
> >> Luben
> >>
> >>>
> >>>
> >>> Takashi
> >>>
> >>> ===
> >>>
> >>> Takashi Iwai (3):
> >>> drm/amd/display: Fix kernel panic by dal_gpio_open() error
> >>> drm/amd/display: Don't invoke kgdb_breakpoint() unconditionally
> >>> drm/amd/display: Clean up debug macros
> >>>
> >>> drivers/gpu/drm/amd/display/Kconfig | 1 +
> >>> drivers/gpu/drm/amd/display/dc/gpio/gpio_base.c | 4 +--
> >>> drivers/gpu/drm/amd/display/dc/os_types.h | 33 +++++++++----------------
> >>> 3 files changed, 15 insertions(+), 23 deletions(-)
> >>>
> >>
> >> _______________________________________________
> >> amd-gfx mailing list
> >> amd-gfx@lists.freedesktop.org
> >> https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> > _______________________________________________
> > amd-gfx mailing list
> > amd-gfx@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/amd-gfx
> >
>
^ permalink raw reply [flat|nested] 8+ messages in thread