[PATCH v2 3/3] drm/panthor: Actually suspend IRQs in the unplug path

[Boris Brezillon <boris.brezillon@collabora.com>]

panthor_xxx_irq_suspend() doesn't mask the interrupts if drm_dev_unplug()
has been called, which is always the case when our panthor_xxx_unplug()
helpers are called. Fix that by introducing a panthor_xxx_unplug() helper
that does what panthor_xxx_irq_suspend() except it does it
unconditionally.

v2:
- Add Steve's R-b

Fixes: 5fe909cae118 ("drm/panthor: Add the device logical block")
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Steven Price <steven.price@arm.com>
---
Found inadvertently while debugging another issue. I guess I managed to
call rmmod during a PING and that led to the FW interrupt handler
being executed after the device suspend happened.
---
 drivers/gpu/drm/panthor/panthor_device.h | 8 ++++++++
 drivers/gpu/drm/panthor/panthor_fw.c     | 2 +-
 drivers/gpu/drm/panthor/panthor_gpu.c    | 2 +-
 drivers/gpu/drm/panthor/panthor_mmu.c    | 2 +-
 4 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_device.h b/drivers/gpu/drm/panthor/panthor_device.h
index 3a930a368ae1..5634e9490c7f 100644
--- a/drivers/gpu/drm/panthor/panthor_device.h
+++ b/drivers/gpu/drm/panthor/panthor_device.h
@@ -321,6 +321,14 @@ static irqreturn_t panthor_ ## __name ## _irq_threaded_handler(int irq, void *da
 	return ret;										\
 }												\
 												\
+static inline void panthor_ ## __name ## _irq_unplug(struct panthor_irq *pirq)			\
+{												\
+	pirq->mask = 0;										\
+	gpu_write(pirq->ptdev, __reg_prefix ## _INT_MASK, 0);					\
+	synchronize_irq(pirq->irq);								\
+	atomic_set(&pirq->suspended, true);							\
+}												\
+												\
 static inline void panthor_ ## __name ## _irq_suspend(struct panthor_irq *pirq)			\
 {												\
 	int cookie;										\
diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index 33c87a59834e..7a9710a38c5f 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -1128,7 +1128,7 @@ void panthor_fw_unplug(struct panthor_device *ptdev)
 
 	/* Make sure the IRQ handler can be called after that point. */
 	if (ptdev->fw->irq.irq)
-		panthor_job_irq_suspend(&ptdev->fw->irq);
+		panthor_job_irq_unplug(&ptdev->fw->irq);
 
 	panthor_fw_stop(ptdev);
 
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
index 6dbbc4cfbe7e..b84c5b650fd9 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -174,7 +174,7 @@ void panthor_gpu_unplug(struct panthor_device *ptdev)
 	unsigned long flags;
 
 	/* Make sure the IRQ handler is not running after that point. */
-	panthor_gpu_irq_suspend(&ptdev->gpu->irq);
+	panthor_gpu_irq_unplug(&ptdev->gpu->irq);
 
 	/* Wake-up all waiters. */
 	spin_lock_irqsave(&ptdev->gpu->reqs_lock, flags);
diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c
index fdd35249169f..1f333cdded0f 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -2622,7 +2622,7 @@ int panthor_vm_prepare_mapped_bos_resvs(struct drm_exec *exec, struct panthor_vm
  */
 void panthor_mmu_unplug(struct panthor_device *ptdev)
 {
-	panthor_mmu_irq_suspend(&ptdev->mmu->irq);
+	panthor_mmu_irq_unplug(&ptdev->mmu->irq);
 
 	mutex_lock(&ptdev->mmu->as.slots_lock);
 	for (u32 i = 0; i < ARRAY_SIZE(ptdev->mmu->as.slots); i++) {
-- 
2.44.0