ASoC: macaudio: Fix PD link double-frees?

Signed-off-by: Hector Martin <marcan@marcan.st>

Author: marcan

sound/soc/apple/mca.c

@@ -296,6 +296,7 @@ static int mca_fe_enable_clocks(struct mca_cluster *cl)
 	 * the power state driver would error out on seeing the device
 	 * as clock-gated.
 	 */
+	WARN_ON(cl->pd_link);
 	cl->pd_link = device_link_add(mca->dev, cl->pd_dev,
 				      DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
 					      DL_FLAG_RPM_ACTIVE);
@@ -319,7 +320,11 @@ static void mca_fe_disable_clocks(struct mca_cluster *cl)
 	mca_modify(cl, REG_SYNCGEN_STATUS, SYNCGEN_STATUS_EN, 0);
 	mca_modify(cl, REG_STATUS, STATUS_MCLK_EN, 0);
 
-	device_link_del(cl->pd_link);
+	if (cl->pd_link) {
+		device_link_del(cl->pd_link);
+		cl->pd_link = NULL;
+	}
+
 	clk_disable_unprepare(cl->clk_parent);
 }
 
@@ -389,6 +394,7 @@ static int mca_fe_prepare(struct snd_pcm_substream *substream,
 	if (!cl->syncgen_in_use) {
 		int port = ffs(mca_fe_get_portmask(substream)) - 1;
 
+		WARN_ON(cl->pd_link);
 		cl->pd_link = device_link_add(mca->dev, cl->pd_dev,
 					      DL_FLAG_STATELESS | DL_FLAG_PM_RUNTIME |
 						DL_FLAG_RPM_ACTIVE);
@@ -421,8 +427,10 @@ static int mca_fe_hw_free(struct snd_pcm_substream *substream,
 		return 0;
 
 	mca_modify(cl, REG_SYNCGEN_STATUS, SYNCGEN_STATUS_EN, 0);
-	if (cl->pd_link)
+	if (cl->pd_link) {
 		device_link_del(cl->pd_link);
+		cl->pd_link = NULL;
+	}
 
 	return 0;
 }
@@ -1108,8 +1116,10 @@ static void apple_mca_release(struct mca_data *mca)
 			dev_pm_domain_detach(cl->pd_dev, true);
 	}
 
-	if (mca->pd_link)
+	if (mca->pd_link) {
 		device_link_del(mca->pd_link);
+		mca->pd_link = NULL;
+	}
 
 	if (!IS_ERR_OR_NULL(mca->pd_dev))
 		dev_pm_domain_detach(mca->pd_dev, true);