Re: [PATCH v1] drm/xe/guc: Allow GuC CT for wedged device

[Raag Jadav <raag.jadav@intel.com>]

On Tue, Aug 25, 2026 at 11:39:44AM +0200, Laguna, Lukasz wrote:
> On 8/21/2026 14:21, Raag Jadav wrote:
> > Commit 50fa9acac26f ("drm/xe/guc: distinguish wedged from recoverable
> > cancellation") introduced distinguishable error codes for g2h failure
> > cases, but also blocked GuC CT for wedged device. This is problematic
> > in cases where we want to prevent user from accessing the device but
> > also keep GuC CT functioning on temporarily wedged device. First user
> > of such requirement is PCIe FLR handling where we require uC firmware
> > loading while the device is temporarily wedged.
> > 
> > Fixes: 50fa9acac26f ("drm/xe/guc: distinguish wedged from recoverable cancellation")
> > Signed-off-by: Raag Jadav <raag.jadav@intel.com>
> > ---
> >   drivers/gpu/drm/xe/xe_guc_ct.c | 8 --------
> >   1 file changed, 8 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_guc_ct.c b/drivers/gpu/drm/xe/xe_guc_ct.c
> > index 5c4733da385c..97e38147effd 100644
> > --- a/drivers/gpu/drm/xe/xe_guc_ct.c
> > +++ b/drivers/gpu/drm/xe/xe_guc_ct.c
> > @@ -1062,11 +1062,6 @@ static int __guc_ct_send_locked(struct xe_guc_ct *ct, const u32 *action,
> >   	xe_gt_assert(gt, g2h_len || !num_g2h);
> >   	lockdep_assert_held(&ct->lock);
> > -	if (xe_device_wedged(ct_to_xe(ct))) {
> > -		ret = -ENOTRECOVERABLE;
> > -		goto out;
> > -	}
> > -
> >   	if (unlikely(ct->ctbs.h2g.info.broken)) {
> >   		ret = -EPIPE;
> >   		goto out;
> > @@ -1813,9 +1808,6 @@ static int g2h_read(struct xe_guc_ct *ct, u32 *msg, bool fast_path)
> >   	xe_gt_assert(gt, xe_guc_ct_initialized(ct));
> >   	lockdep_assert_held(&ct->fast_lock);
> > -	if (xe_device_wedged(xe))
> > -		return -ENOTRECOVERABLE;
> > -
> >   	if (ct->state == XE_GUC_CT_STATE_DISABLED)
> >   		return -ENODEV;
> 
> There's also third instance in guc_ct_send_recv().
> 
> Shouldn't we distinguish between temporary and permanent wedge here rather
> than removing the checks entirely?

I thought of adding a xe_device_wedged_perm() but this would create
confusion with existing xe_device_wedged() regardling it's usage.
So perhaps we need a better name? Or a better idea? Open to suggestions.

> And it looks like it should be a part of the FLR series. This patch doesn't
> make sense without this series, and FLR series doesn't work without it.
> I'm also not sure if it deserves the fixes tag, it wasn't broken at the
> time.

Agree, will add it as part of FLR series once we have some conclusion.

Raag