ASoC: wm_adsp: Add locking to wm_adsp2_bus_error

[ Upstream commit a2225a6d155fcb247fe4c6d87f7c91807462966d ]

Best to lock across handling the bus error to ensure the DSP doesn't
change power state as we are reading the status registers.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

sound/soc/codecs/wm_adsp.c

@@ -3819,11 +3819,13 @@ irqreturn_t wm_adsp2_bus_error(struct wm_adsp *dsp)
 	struct regmap *regmap = dsp->regmap;
 	int ret = 0;
 
+	mutex_lock(&dsp->pwr_lock);
+
 	ret = regmap_read(regmap, dsp->base + ADSP2_LOCK_REGION_CTRL, &val);
 	if (ret) {
 		adsp_err(dsp,
 			"Failed to read Region Lock Ctrl register: %d\n", ret);
-		return IRQ_HANDLED;
+		goto error;
 	}
 
 	if (val & ADSP2_WDT_TIMEOUT_STS_MASK) {
@@ -3842,7 +3844,7 @@ irqreturn_t wm_adsp2_bus_error(struct wm_adsp *dsp)
 			adsp_err(dsp,
 				 "Failed to read Bus Err Addr register: %d\n",
 				 ret);
-			return IRQ_HANDLED;
+			goto error;
 		}
 
 		adsp_err(dsp, "bus error address = 0x%x\n",
@@ -3855,7 +3857,7 @@ irqreturn_t wm_adsp2_bus_error(struct wm_adsp *dsp)
 			adsp_err(dsp,
 				 "Failed to read Pmem Xmem Err Addr register: %d\n",
 				 ret);
-			return IRQ_HANDLED;
+			goto error;
 		}
 
 		adsp_err(dsp, "xmem error address = 0x%x\n",
@@ -3868,6 +3870,9 @@ irqreturn_t wm_adsp2_bus_error(struct wm_adsp *dsp)
 	regmap_update_bits(regmap, dsp->base + ADSP2_LOCK_REGION_CTRL,
 			   ADSP2_CTRL_ERR_EINT, ADSP2_CTRL_ERR_EINT);
 
+error:
+	mutex_unlock(&dsp->pwr_lock);
+
 	return IRQ_HANDLED;
 }
 EXPORT_SYMBOL_GPL(wm_adsp2_bus_error);