| Message ID | pusppq5ybyszau2oocboj3mtj5x574gwij323jlclm5zxvimmu@mnfg6odxbpsv (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v3] drm/i915/gt: Use spin_lock_irqsave() in interruptible context | expand |
On 16.01.2025 11:40, Krzysztof Karas wrote: > spin_lock/unlock() functions used in interrupt contexts could > result in a deadlock, as seen in GitLab issue #13399: > https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13399, > which occurs when interrupt comes in while holding a lock. > > Try to remedy the problem by saving irq state before spin lock > acquisition. > > v2: add irqs' state save/restore calls to all locks/unlocks in > signal_irq_work() execution (Maciej) > > v3: use with spin_lock_irqsave() in guc_lrc_desc_unpin() instead > of other lock/unlock calls and add Fixes and Cc tags (Tvrtko); > change title and commit message > > Signed-off-by: Krzysztof Karas <krzysztof.karas@intel.com> > Fixes: 2f2cc53b5fe7 ("drm/i915/guc: Close deregister-context race against CT-loss") > Cc: <stable@vger.kernel.org> # v6.9+ > --- > drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > index 12f1ba7ca9c1..29d9c81473cc 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > @@ -3433,10 +3433,10 @@ static inline int guc_lrc_desc_unpin(struct intel_context *ce) > */ > ret = deregister_context(ce, ce->guc_id.id); > if (ret) { > - spin_lock(&ce->guc_state.lock); > + spin_lock_irqsave(&ce->guc_state.lock, flags); > set_context_registered(ce); > clr_context_destroyed(ce); > - spin_unlock(&ce->guc_state.lock); > + spin_unlock_irqrestore(&ce->guc_state.lock, flags); > /* > * As gt-pm is awake at function entry, intel_wakeref_put_async merely decrements > * the wakeref immediately but per function spec usage call this after unlock. Looked at this and wasn't seeing it. There is spin_lock_irqsave() used earlier. Reviewed-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index 12f1ba7ca9c1..29d9c81473cc 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -3433,10 +3433,10 @@ static inline int guc_lrc_desc_unpin(struct intel_context *ce) */ ret = deregister_context(ce, ce->guc_id.id); if (ret) { - spin_lock(&ce->guc_state.lock); + spin_lock_irqsave(&ce->guc_state.lock, flags); set_context_registered(ce); clr_context_destroyed(ce); - spin_unlock(&ce->guc_state.lock); + spin_unlock_irqrestore(&ce->guc_state.lock, flags); /* * As gt-pm is awake at function entry, intel_wakeref_put_async merely decrements * the wakeref immediately but per function spec usage call this after unlock.
spin_lock/unlock() functions used in interrupt contexts could result in a deadlock, as seen in GitLab issue #13399: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13399, which occurs when interrupt comes in while holding a lock. Try to remedy the problem by saving irq state before spin lock acquisition. v2: add irqs' state save/restore calls to all locks/unlocks in signal_irq_work() execution (Maciej) v3: use with spin_lock_irqsave() in guc_lrc_desc_unpin() instead of other lock/unlock calls and add Fixes and Cc tags (Tvrtko); change title and commit message Signed-off-by: Krzysztof Karas <krzysztof.karas@intel.com> Fixes: 2f2cc53b5fe7 ("drm/i915/guc: Close deregister-context race against CT-loss") Cc: <stable@vger.kernel.org> # v6.9+ --- drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)