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: [email protected]
Closes:
https://sashiko.dev/#/patchset/[email protected]?part=1
Signed-off-by: Boris Brezillon <[email protected]>
---
drivers/gpu/drm/panthor/panthor_device.h | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/panthor/panthor_device.h
b/drivers/gpu/drm/panthor/panthor_device.h
index 35679bfa1f3a..a39386bd6382 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -512,9 +512,6 @@ 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,
\
@@ -522,6 +519,13 @@ 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;
\
}
\
--
2.54.0
