[PATCH v3 2/5] drm/panthor: Be robust against runtime PM resume failures in the suspend path

[Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>]

The runtime PM resume operation is not guaranteed to succeed, but if it
fails, the device should be in a suspended state. Make sure we're robust
to resume failures in the unplug path.

v3:
- Fix typo
- Add R-bs

v2:
- Move the bit that belonged in the next commit
- Drop the panthor_device_unplug() changes

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
Reviewed-by: Adrian Larumbe <adrian.larumbe@xxxxxxxxxxxxx>
Reviewed-by: Steven Price <steven.price@xxxxxxx>
---
 drivers/gpu/drm/panthor/panthor_fw.c  | 14 +++++++++-----
 drivers/gpu/drm/panthor/panthor_gpu.c |  3 ++-
 drivers/gpu/drm/panthor/panthor_mmu.c |  3 ++-
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index ebf8980ca9a3..02789558788d 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -12,6 +12,7 @@
 #include <linux/iosys-map.h>
 #include <linux/mutex.h>
 #include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
 
 #include <drm/drm_drv.h>
 #include <drm/drm_managed.h>
@@ -1190,11 +1191,13 @@ void panthor_fw_unplug(struct panthor_device *ptdev)
 
 	cancel_delayed_work_sync(&ptdev->fw->watchdog.ping_work);
 
-	/* Make sure the IRQ handler can be called after that point. */
-	if (ptdev->fw->irq.irq)
-		panthor_job_irq_suspend(&ptdev->fw->irq);
+	if (!IS_ENABLED(CONFIG_PM) || pm_runtime_active(ptdev->base.dev)) {
+		/* Make sure the IRQ handler cannot be called after that point. */
+		if (ptdev->fw->irq.irq)
+			panthor_job_irq_suspend(&ptdev->fw->irq);
 
-	panthor_fw_stop(ptdev);
+		panthor_fw_stop(ptdev);
+	}
 
 	list_for_each_entry(section, &ptdev->fw->sections, node)
 		panthor_kernel_bo_destroy(section->mem);
@@ -1207,7 +1210,8 @@ void panthor_fw_unplug(struct panthor_device *ptdev)
 	panthor_vm_put(ptdev->fw->vm);
 	ptdev->fw->vm = NULL;
 
-	panthor_gpu_power_off(ptdev, L2, ptdev->gpu_info.l2_present, 20000);
+	if (!IS_ENABLED(CONFIG_PM) || pm_runtime_active(ptdev->base.dev))
+		panthor_gpu_power_off(ptdev, L2, ptdev->gpu_info.l2_present, 20000);
 }
 
 /**
diff --git a/drivers/gpu/drm/panthor/panthor_gpu.c b/drivers/gpu/drm/panthor/panthor_gpu.c
index 0f3cac6ec88e..ee85a371bc38 100644
--- a/drivers/gpu/drm/panthor/panthor_gpu.c
+++ b/drivers/gpu/drm/panthor/panthor_gpu.c
@@ -180,7 +180,8 @@ 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);
+	if (!IS_ENABLED(CONFIG_PM) || pm_runtime_active(ptdev->base.dev))
+		panthor_gpu_irq_suspend(&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 9478ee2093d1..6716463903bc 100644
--- a/drivers/gpu/drm/panthor/panthor_mmu.c
+++ b/drivers/gpu/drm/panthor/panthor_mmu.c
@@ -2681,7 +2681,8 @@ 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);
+	if (!IS_ENABLED(CONFIG_PM) || pm_runtime_active(ptdev->base.dev))
+		panthor_mmu_irq_suspend(&ptdev->mmu->irq);
 
 	mutex_lock(&ptdev->mmu->as.slots_lock);
 	for (u32 i = 0; i < ARRAY_SIZE(ptdev->mmu->as.slots); i++) {
-- 
2.47.0