[PATCH 09/10] drm/panthor: Process FW events in IRQ context

[Boris Brezillon]

Now that everything is set to allow processing FW events in IRQ context,
go for it. This should reduce the dma_fence signaling latency.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/panthor/panthor_fw.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/panthor/panthor_fw.c b/drivers/gpu/drm/panthor/panthor_fw.c
index f5e0ceca4130..05c632913359 100644
--- a/drivers/gpu/drm/panthor/panthor_fw.c
+++ b/drivers/gpu/drm/panthor/panthor_fw.c
@@ -1087,9 +1087,38 @@ static void panthor_job_irq_handler(struct panthor_irq *pirq, u32 status)
 	}
 }
 
+static irqreturn_t panthor_job_irq_raw_handler(int irq, void *data)
+{
+	struct panthor_irq *pirq = data;
+
+	if (!gpu_read(pirq->iomem, INT_STAT))
+		return IRQ_NONE;
+
+	scoped_guard(spinlock_irqsave, &pirq->mask_lock) {
+		if (pirq->state != PANTHOR_IRQ_STATE_ACTIVE)
+			return IRQ_NONE;
+
+		pirq->state = PANTHOR_IRQ_STATE_PROCESSING;
+	}
+
+	panthor_job_irq_handler(pirq, gpu_read(pirq->iomem, INT_RAWSTAT));
+
+	scoped_guard(spinlock_irqsave, &pirq->mask_lock) {
+		if (pirq->state == PANTHOR_IRQ_STATE_PROCESSING)
+			pirq->state = PANTHOR_IRQ_STATE_ACTIVE;
+	}
+
+	return IRQ_HANDLED;
+}
+
 static irqreturn_t panthor_job_irq_threaded_handler(int irq, void *data)
 {
-	return panthor_irq_default_threaded_handler(data, panthor_job_irq_handler);
+	struct panthor_irq *pirq = data;
+
+	/* We never return IRQ_WAKE_THREAD, so we're not supposed to be called. */
+	drm_WARN_ON_ONCE(&pirq->ptdev->base,
+			 "threaded IRQ handler should never be called.");
+	return IRQ_NONE;
 }
 
 static int panthor_fw_start(struct panthor_device *ptdev)
@@ -1489,7 +1518,7 @@ int panthor_fw_init(struct panthor_device *ptdev)
 
 	ret = panthor_irq_request(ptdev, &fw->irq, irq, 0,
 				  ptdev->iomem + JOB_INT_BASE, "job",
-				  panthor_irq_default_raw_handler,
+				  panthor_job_irq_raw_handler,
 				  panthor_job_irq_threaded_handler);
 	if (ret) {
 		drm_err(&ptdev->base, "failed to request job irq");

-- 
2.53.0