[PATCH 01/12] slimbus: qcom-ngd-ctrl: check for device runtime PM status during ISR

[Srinivas Kandagatla]

From: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>

Slimbus core interrupt is getting fired after suspend. At this point
ADSP slimbus hardware is off with gated clocks which is leading to an
unclocked access when HLOS slimbus tried to read the interrupt
status register in the ISR.

Co-developed-by: Chandana Kishori Chiluveru <cchiluve@xxxxxxxxxxxxxx>
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@xxxxxxxxxxxxxx>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
---
 drivers/slimbus/qcom-ngd-ctrl.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/slimbus/qcom-ngd-ctrl.c b/drivers/slimbus/qcom-ngd-ctrl.c
index 76c5e446d243..964adf77b51b 100644
--- a/drivers/slimbus/qcom-ngd-ctrl.c
+++ b/drivers/slimbus/qcom-ngd-ctrl.c
@@ -763,7 +763,14 @@ static irqreturn_t qcom_slim_ngd_interrupt(int irq, void *d)
 {
 	struct qcom_slim_ngd_ctrl *ctrl = d;
 	void __iomem *base = ctrl->ngd->base;
-	u32 stat = readl(base + NGD_INT_STAT);
+	u32 stat;
+
+	if (pm_runtime_suspended(ctrl->ctrl.dev)) {
+		dev_warn_once(ctrl->dev, "Interrupt received while suspended\n");
+		return IRQ_NONE;
+	}
+
+	stat = readl(base + NGD_INT_STAT);
 
 	if ((stat & NGD_INT_MSG_BUF_CONTE) ||
 		(stat & NGD_INT_MSG_TX_INVAL) || (stat & NGD_INT_DEV_ERR) ||
-- 
2.25.1