From: Viorel Suman <viorel.suman@nxp.com>
Date: Thu, 18 Apr 2019 12:28:04 +0000 (+0300)
Subject: MLK-21484-3: ASoC: fsl_sai: ensure clk is unprepared before reparent
X-Git-Tag: rel_imx_4.19.35_1.1.0~698
X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=e146b5f34492cd046187b92eb4ae37f238557eb9;p=linux.git

MLK-21484-3: ASoC: fsl_sai: ensure clk is unprepared before reparent

On recent kernels clks which are marked with CLK_SET_RATE_GATE are
"protected" against further changes at clk_prepare time, including clk
reparent. Wrap clk set_parent and set_rate operations with
disable_unprepare and prepare_enable.

Signed-off-by: Viorel Suman <viorel.suman@nxp.com>
---

diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
index febc6127d8cb..1b6a5b92a8fb 100644
--- a/sound/soc/fsl/fsl_sai.c
+++ b/sound/soc/fsl/fsl_sai.c
@@ -242,6 +242,7 @@ static int fsl_sai_set_mclk_rate(struct snd_soc_dai *dai, int clk_id,
 	struct fsl_sai *sai = snd_soc_dai_get_drvdata(dai);
 	struct clk *p = sai->mclk_clk[clk_id], *pll = 0, *npll = 0;
 	u64 ratio = freq;
+	bool reparent = false;
 	int ret;
 
 	while (p && sai->pll8k_clk && sai->pll11k_clk) {
@@ -255,28 +256,31 @@ static int fsl_sai_set_mclk_rate(struct snd_soc_dai *dai, int clk_id,
 		p = pp;
 	}
 
-	if (pll) {
-		npll = (do_div(ratio, 8000) ? sai->pll11k_clk : sai->pll8k_clk);
-		if (!clk_is_match(pll, npll)) {
-			if (sai->mclk_streams == 0) {
-				ret = clk_set_parent(p, npll);
-				if (ret < 0)
-					dev_warn(dai->dev,
-						"failed to set parent %s: %d\n",
-						__clk_get_name(npll), ret);
-			} else {
-				dev_err(dai->dev,
-					"PLL %s is in use by a running stream.\n",
-					__clk_get_name(pll));
-				return -EINVAL;
-			}
+	npll = (do_div(ratio, 8000) ? sai->pll11k_clk : sai->pll8k_clk);
+	if (pll && !clk_is_match(pll, npll)) {
+		if (sai->mclk_streams != 0) {
+			dev_err(dai->dev,
+				"PLL %s is in use by a running stream.\n",
+				__clk_get_name(pll));
+			return -EINVAL;
 		}
+		reparent = true;
+	}
+
+	clk_disable_unprepare(sai->mclk_clk[clk_id]);
+	if (reparent) {
+		ret = clk_set_parent(p, npll);
+		if (ret < 0)
+			dev_warn(dai->dev, "failed to set parent %s: %d\n",
+				 __clk_get_name(npll), ret);
 	}
 
 	ret = clk_set_rate(sai->mclk_clk[clk_id], freq);
 	if (ret < 0)
-		dev_err(dai->dev, "failed to set clock rate (%u): %d\n",
-				freq, ret);
+		dev_warn(dai->dev, "failed to set clock rate (%u): %d\n", freq,
+			 ret);
+	clk_prepare_enable(sai->mclk_clk[clk_id]);
+
 	return ret;
 }