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drm/i915/gt: Use spin_lock_irqsave() in interruptible context

spin_lock/unlock() functions used in interrupt contexts could
result in a deadlock, as seen in GitLab issue #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

Fixes: 2f2cc53b5f ("drm/i915/guc: Close deregister-context race against CT-loss")
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/13399
Signed-off-by: Krzysztof Karas <krzysztof.karas@intel.com>
Cc: <stable@vger.kernel.org> # v6.9+
Reviewed-by: Maciej Patelczyk <maciej.patelczyk@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/pusppq5ybyszau2oocboj3mtj5x574gwij323jlclm5zxvimmu@mnfg6odxbpsv
(cherry picked from commit c088387ddd6482b40f21ccf23db1125e8fa4af7e)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
This commit is contained in:
Krzysztof Karas 2025-01-16 10:40:46 +00:00 committed by Rodrigo Vivi
parent 0ad2507d5d
commit e49477f7f7
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@ -3449,10 +3449,10 @@ 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.