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From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
To:     Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Srinivas Kandagatla <srinivas.kandagatla@linaro.org>,
        linux-arm-msm@vger.kernel.org, alsa-devel@alsa-project.org,
        linux-kernel@vger.kernel.org
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>,
        Chandana Kishori Chiluveru <cchiluve@codeaurora.org>
Subject: [PATCH 1/2] slimbus: qcom-ngd-ctrl: check for device runtime PM status during ISR
Date:   Wed, 28 Sep 2022 15:20:10 +0200
Message-Id: <20220928132011.455347-1-krzysztof.kozlowski@linaro.org>
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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@codeaurora.org>
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
---
 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 cec11aa106bf..ba36eb5c0de3 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) ||
-- 
2.34.1