[PATCH] media: intel/ipu6: do not handle interrupts when device is disabled

[Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx>]

Some IPU6 devices have shared interrupts. We need to handle properly
case when interrupt is triggered from other device on shared irq line
and IPU6 itself disabled. In such case we get 0xffffffff from
ISR_STATUS register and handle all irq's cases, for what we are not
not prepared and usually hang the whole system.

To avoid the issue use pm_runtime_get_if_active() to check if
the device is enabled and prevent suspending it when we handle irq
until the end of irq. Additionally use synchronize_irq() in suspend

Fixes: ab29a2478e70 ("media: intel/ipu6: add IPU6 buttress interface driver")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Stanislaw Gruszka <stanislaw.gruszka@xxxxxxxxxxxxxxx>
---
 drivers/media/pci/intel/ipu6/ipu6-buttress.c | 13 +++++++++----
 drivers/media/pci/intel/ipu6/ipu6.c          |  3 +++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/media/pci/intel/ipu6/ipu6-buttress.c b/drivers/media/pci/intel/ipu6/ipu6-buttress.c
index e47f84c30e10..edaa285283a1 100644
--- a/drivers/media/pci/intel/ipu6/ipu6-buttress.c
+++ b/drivers/media/pci/intel/ipu6/ipu6-buttress.c
@@ -345,12 +345,16 @@ irqreturn_t ipu6_buttress_isr(int irq, void *isp_ptr)
 	u32 disable_irqs = 0;
 	u32 irq_status;
 	u32 i, count = 0;
+	int active;
 
-	pm_runtime_get_noresume(&isp->pdev->dev);
+	active = pm_runtime_get_if_active(&isp->pdev->dev);
+	if (!active)
+		return IRQ_NONE;
 
 	irq_status = readl(isp->base + reg_irq_sts);
-	if (!irq_status) {
-		pm_runtime_put_noidle(&isp->pdev->dev);
+	if (irq_status == 0 || WARN_ON_ONCE(irq_status == 0xffffffffu)) {
+		if (active > 0)
+			pm_runtime_put_noidle(&isp->pdev->dev);
 		return IRQ_NONE;
 	}
 
@@ -426,7 +430,8 @@ irqreturn_t ipu6_buttress_isr(int irq, void *isp_ptr)
 		writel(BUTTRESS_IRQS & ~disable_irqs,
 		       isp->base + BUTTRESS_REG_ISR_ENABLE);
 
-	pm_runtime_put(&isp->pdev->dev);
+	if (active > 0)
+		pm_runtime_put(&isp->pdev->dev);
 
 	return ret;
 }
diff --git a/drivers/media/pci/intel/ipu6/ipu6.c b/drivers/media/pci/intel/ipu6/ipu6.c
index 7fb707d35309..91718eabd74e 100644
--- a/drivers/media/pci/intel/ipu6/ipu6.c
+++ b/drivers/media/pci/intel/ipu6/ipu6.c
@@ -752,6 +752,9 @@ static void ipu6_pci_reset_done(struct pci_dev *pdev)
  */
 static int ipu6_suspend(struct device *dev)
 {
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	synchronize_irq(pdev->irq);
 	return 0;
 }
 
-- 
2.46.1