On 7/11/2025 3:16 AM, Raag Jadav wrote:
On Thu, Jul 10, 2025 at 03:00:06PM -0400, Rodrigo Vivi wrote:
On Thu, Jul 10, 2025 at 01:24:52PM +0300, Raag Jadav wrote:
On Thu, Jul 10, 2025 at 11:37:14AM +0200, Christian König wrote:
On 10.07.25 11:01, Simona Vetter wrote:
On Wed, Jul 09, 2025 at 12:52:05PM -0400, Rodrigo Vivi wrote:
On Wed, Jul 09, 2025 at 05:18:54PM +0300, Raag Jadav wrote:
On Wed, Jul 09, 2025 at 04:09:20PM +0200, Christian König wrote:
On 09.07.25 15:41, Simona Vetter wrote:
On Wed, Jul 09, 2025 at 04:50:13PM +0530, Riana Tauro wrote:
Certain errors can cause the device to be wedged and may
require a vendor specific recovery method to restore normal
operation.
Add a recovery method 'WEDGED=vendor-specific' for such errors. Vendors
must provide additional recovery documentation if this method
is used.
v2: fix documentation (Raag)
Cc: André Almeida <andrealm...@igalia.com>
Cc: Christian König <christian.koe...@amd.com>
Cc: David Airlie <airl...@gmail.com>
Cc: <dri-devel@lists.freedesktop.org>
Suggested-by: Raag Jadav <raag.ja...@intel.com>
Signed-off-by: Riana Tauro <riana.ta...@intel.com>
I'm not really understanding what this is useful for, maybe concrete
example in the form of driver code that uses this, and some tool or
documentation steps that should be taken for recovery?
The case here is when FW underneath identified something badly corrupted on
FW land and decided that only a firmware-flashing could solve the day and
raise interrupt to the driver. At that point we want to wedge, but immediately
hint the admin the recommended action.
The recovery method for this particular case is to flash in a new firmware.
The issues I'm seeing here is that eventually we'll get different
vendor-specific recovery steps, and maybe even on the same device, and
that leads us to an enumeration issue. Since it's just a string and an
enum I think it'd be better to just allocate a new one every time there's
a new strange recovery method instead of this opaque approach.
That is exactly the opposite of what we discussed so far.
Sorry, I missed that context.
The original idea was to add a firmware-flush recovery method which
looked a bit wage since it didn't give any information on what to do
exactly.
That's why I suggested to add a more generic vendor-specific event
with refers to the documentation and system log to see what actually
needs to be done.
Otherwise we would end up with events like firmware-flash, update FW
image A, update FW image B, FW version mismatch etc....
Yeah, that's kinda what I expect to happen, and we have enough numbers for
this all to not be an issue.
Agree. Any newly allocated method that is specific to a vendor is going to
be opaque anyway, since it can't be generic for all drivers. This just helps
reduce the noise in DRM core.
And yes, there could be different vendor-specific cases for the same driver
and the driver should be able to provide the means to distinguish between
them.
Sim, what's your take on this then?
Should we get back to the original idea of firmware-flash?
Maybe intel-firmware-flash or something, meaning prefix with the vendor?
The reason I think it should be specific is because I'm assuming you want
to script this. And if you have a big fleet with different vendors, then
"vendor-specific" doesn't tell you enough. But if it's something like
$vendor-$magic_step then it does become scriptable, and we do have have a
place to put some documentation on what you should do instead.
If the point of this interface isn't that it's scriptable, then I'm not
sure why it needs to be an uevent?
You should probably read up on the previous discussion, cause that is exactly
what I asked as well :)
And no, it should *not* be scripted. That would be a bit brave for a firmware
update where you should absolutely not power down the system for example.
I also don't like the idea or even the thought of scripting something like
a firmware-flash. But only to fail with a better pin point to make admin
lives easier with a notification.
In my understanding the new value "vendor-specific" basically means it is a known issue
with a documented solution, while "unknown" means the driver has no idea how to solve it.
Exactly, the hardware and firmware are giving the indication of what should be
done. It is not 'unknown'.
Yes, and since the recovery procedure is defined and known to the consumer,
it can potentially be automated (atleast for non-firmware cases).
I guess if you all want to stick with vendor-specific then I think that's
Well, I would honestly prefer a direct firmware-flash, but if that is not
usable by other vendors and there's a push back on that, let's go with
the vendor-specific then.
I think the procedure for firmware-flash is vendor specific, so the wedged event
alone is not sufficient either way. The consumer will need more guidance from
vendor documentation.
Procedure of firmware-flash is vendor specific, but the term
'firmware-flash' is still generic. The patch doesn't mention any vendor
specific firmware or procedure. The push back was for the number of
macros that can be added for other operations.
With vendor-specific method, the driver has the opportunity to cover as many
cases as it wants without having to create a new method everytime, and face the
same dilemma of being vendor agnostic.
ok with me too, but the docs should at least explain how to figure out
from the uevent which vendor you're on with a small example. What I'm
worried is that if we have this on multiple drivers userspace will
otherwise make a complete mess and might want to run the wrong recovery
steps.
The device id along with driver can be identified from uevent (probably
available inside DEVPATH somewhere) to distinguish the vendor. So the consumer
already knows if the device fits the criteria for recovery.
I think ideally, no matter what, we'd have a concrete driver patch which
then also comes with the documentation for what exactly you're supposed to
do as something you can script. And not just this stand-alone patch here.
Perhaps the rest of the series didn't make it to dri-devel, which will answer
most of the above.
Riana, could you please try to provide a bit more documentation like Sima
asked and re-send the entire series to dri-devel?
Sure will send the entire series to dri-devel. The documentation is
present in the series.
With the ideas in this thread also documented so that we don't end up repeating
the same discussion.
It is mentioned in cover letter but i didn't send it to dri-devel. will
add more details
Thanks
Riana
Raag
---
Documentation/gpu/drm-uapi.rst | 9 +++++----
drivers/gpu/drm/drm_drv.c | 2 ++
include/drm/drm_device.h | 4 ++++
3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/Documentation/gpu/drm-uapi.rst b/Documentation/gpu/drm-uapi.rst
index 263e5a97c080..c33070bdb347 100644
--- a/Documentation/gpu/drm-uapi.rst
+++ b/Documentation/gpu/drm-uapi.rst
@@ -421,10 +421,10 @@ Recovery
Current implementation defines three recovery methods, out of which, drivers
can use any one, multiple or none. Method(s) of choice will be sent in the
uevent environment as ``WEDGED=<method1>[,..,<methodN>]`` in order of less to
-more side-effects. If driver is unsure about recovery or method is unknown
-(like soft/hard system reboot, firmware flashing, physical device replacement
-or any other procedure which can't be attempted on the fly), ``WEDGED=unknown``
-will be sent instead.
+more side-effects. If recovery method is specific to vendor
+``WEDGED=vendor-specific`` will be sent and userspace should refer to vendor
+specific documentation for further recovery steps. If driver is unsure about
+recovery or method is unknown, ``WEDGED=unknown`` will be sent instead
Userspace consumers can parse this event and attempt recovery as per the
following expectations.
@@ -435,6 +435,7 @@ following expectations.
none optional telemetry collection
rebind unbind + bind driver
bus-reset unbind + bus reset/re-enumeration + bind
+ vendor-specific vendor specific recovery method
unknown consumer policy
=============== ========================================
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index cdd591b11488..0ac723a46a91 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -532,6 +532,8 @@ static const char *drm_get_wedge_recovery(unsigned int opt)
return "rebind";
case DRM_WEDGE_RECOVERY_BUS_RESET:
return "bus-reset";
+ case DRM_WEDGE_RECOVERY_VENDOR:
+ return "vendor-specific";
default:
return NULL;
}
diff --git a/include/drm/drm_device.h b/include/drm/drm_device.h
index 08b3b2467c4c..08a087f149ff 100644
--- a/include/drm/drm_device.h
+++ b/include/drm/drm_device.h
@@ -26,10 +26,14 @@ struct pci_controller;
* Recovery methods for wedged device in order of less to more side-effects.
* To be used with drm_dev_wedged_event() as recovery @method. Callers can
* use any one, multiple (or'd) or none depending on their needs.
+ *
+ * Refer to "Device Wedging" chapter in Documentation/gpu/drm-uapi.rst for more
+ * details.
*/
#define DRM_WEDGE_RECOVERY_NONE BIT(0) /* optional telemetry
collection */
#define DRM_WEDGE_RECOVERY_REBIND BIT(1) /* unbind + bind driver */
#define DRM_WEDGE_RECOVERY_BUS_RESET BIT(2) /* unbind + reset bus device +
bind */
+#define DRM_WEDGE_RECOVERY_VENDOR BIT(3) /* vendor specific recovery
method */
/**
* struct drm_wedge_task_info - information about the guilty task of a wedge
dev
--
2.47.1
