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| author | Boris Brezillon <boris.brezillon@collabora.com> | 2026-06-25 14:40:31 +0200 |
|---|---|---|
| committer | Liviu Dudau <liviu.dudau@arm.com> | 2026-06-30 15:26:55 +0100 |
| commit | fe4c05a59018964bac7923338706371fff3c09ef (patch) | |
| tree | 13fc1cb67a1536109c6f33f99c9e879d20c6535d /drivers | |
| parent | b39436d0ba1571dbcda69d20ec567344b3eecfc7 (diff) | |
| download | linux-next-fe4c05a59018964bac7923338706371fff3c09ef.tar.gz linux-next-fe4c05a59018964bac7923338706371fff3c09ef.zip | |
drm/panthor: Fix theoretical IOMEM access in suspended state
In theory, our hardirq handler can be called while the device (and
thus the panthor_irq) is suspended, because the IRQ line is shared.
In practice though, in all the designs we've seen, the line is only
shared within the GPU, and because sub-component suspend state is
consistent (all-suspended or all-resumed), we shouldn't end up with
an interrupt triggered while we're suspended.
Fix the problem anyway, if nothing else, for our sanity.
Fixes: 0b2d86670a84 ("drm/panthor: Rework panthor_irq::suspended into panthor_irq::state")
Reported-by: sashiko-bot@kernel.org
Closes: https://sashiko.dev/#/patchset/20260625-panthor-signal-from-irq-v4-0-3d2908912afa@collabora.com?part=1
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
Link: https://patch.msgid.link/20260625-panthor-misc-fixes-v1-5-b67ed973fea6@collabora.com
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/gpu/drm/panthor/panthor_device.h | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h index a412a50eec76..291e0de154bc 100644 --- a/drivers/gpu/drm/panthor/panthor_device.h +++ b/drivers/gpu/drm/panthor/panthor_device.h @@ -509,9 +509,6 @@ static irqreturn_t panthor_ ## __name ## _irq_raw_handler(int irq, void *data) struct panthor_irq *pirq = data; \ enum panthor_irq_state old_state; \ \ - if (!gpu_read(pirq->iomem, INT_STAT)) \ - return IRQ_NONE; \ - \ guard(spinlock_irqsave)(&pirq->mask_lock); \ old_state = atomic_cmpxchg(&pirq->state, \ PANTHOR_IRQ_STATE_ACTIVE, \ @@ -519,6 +516,13 @@ static irqreturn_t panthor_ ## __name ## _irq_raw_handler(int irq, void *data) if (old_state != PANTHOR_IRQ_STATE_ACTIVE) \ return IRQ_NONE; \ \ + if (!gpu_read(pirq->iomem, INT_STAT)) { \ + atomic_cmpxchg(&pirq->state, \ + PANTHOR_IRQ_STATE_PROCESSING, \ + PANTHOR_IRQ_STATE_ACTIVE); \ + return IRQ_NONE; \ + } \ + \ gpu_write(pirq->iomem, INT_MASK, 0); \ return IRQ_WAKE_THREAD; \ } \ |