[PATCH v2 08/10] soundwire: qcom: Check clk_prepare_enable() return value

[Lee Jones <lee@kernel.org>]

qcom_swrm_probe(), qcom_swrm_irq_handler(), and swrm_runtime_resume()
ignore the return value of clk_prepare_enable(ctrl->hclk) and proceed
to access controller registers even when enabling the interface clock
fails.  Also jump to err_clk when requesting the wake IRQ fails in
qcom_swrm_probe() so ctrl->hclk is disabled on error.

Check the return value of clk_prepare_enable() in all three callers and
abort register access on failure.

Closes: https://sashiko.dev/#/bug/linux-f65cddc9-08ff-4531-9acf-76981d74d914
Signed-off-by: Lee Jones <lee@kernel.org>
---

v1 => v2: Drop Fixes and Stable tags

 drivers/soundwire/qcom.c | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/soundwire/qcom.c b/drivers/soundwire/qcom.c
index a50efdfc3a6b..785096b232f2 100644
--- a/drivers/soundwire/qcom.c
+++ b/drivers/soundwire/qcom.c
@@ -778,7 +778,9 @@ static irqreturn_t qcom_swrm_irq_handler(int irq, void *dev_id)
 	u32 i;
 	int devnum;
 	int ret = IRQ_HANDLED;
-	clk_prepare_enable(ctrl->hclk);
+
+	if (clk_prepare_enable(ctrl->hclk))
+		return IRQ_NONE;
 
 	ctrl->reg_read(ctrl, ctrl->reg_layout[SWRM_REG_INTERRUPT_STATUS],
 		       &intr_sts);
@@ -1677,7 +1679,9 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 		goto err_init;
 	}
 
-	clk_prepare_enable(ctrl->hclk);
+	ret = clk_prepare_enable(ctrl->hclk);
+	if (ret)
+		goto err_init;
 
 	ctrl->dev = dev;
 	dev_set_drvdata(&pdev->dev, ctrl);
@@ -1733,7 +1737,7 @@ static int qcom_swrm_probe(struct platform_device *pdev)
 						"swr_wake_irq", ctrl);
 		if (ret) {
 			dev_err(dev, "Failed to request soundwire wake irq\n");
-			goto err_init;
+			goto err_clk;
 		}
 	}
 
@@ -1802,13 +1806,15 @@ static int __maybe_unused swrm_runtime_resume(struct device *dev)
 	struct qcom_swrm_ctrl *ctrl = dev_get_drvdata(dev);
 	int ret;
 
+	ret = clk_prepare_enable(ctrl->hclk);
+	if (ret)
+		return ret;
+
 	if (ctrl->wake_irq > 0) {
 		if (!irqd_irq_disabled(irq_get_irq_data(ctrl->wake_irq)))
 			disable_irq_nosync(ctrl->wake_irq);
 	}
 
-	clk_prepare_enable(ctrl->hclk);
-
 	if (ctrl->clock_stop_not_supported) {
 		reinit_completion(&ctrl->enumeration);
 		ctrl->reg_write(ctrl, SWRM_COMP_SW_RESET, 0x01);
-- 
2.56.0.385.gac671c819a-goog