github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-27 17:47:41 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

drm/panthor: Fix theoretical IOMEM access in suspended state

Browse Source 
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: 0b2d86670a ("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
This commit is contained in:
Boris Brezillon 2026-06-25 14:40:31 +02:00 committed by Liviu Dudau
parent b39436d0ba
commit fe4c05a590
1 changed files with 7 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
drivers/gpu/drm/panthor/panthor_device.h
View File

@ -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; \
} \