From: Adrian Alonso <aalonso@freescale.com>
Date: Mon, 14 May 2012 23:02:35 +0000 (-0500)
Subject: ENGR00178459 mxc_spdif: fix read access for debug info
X-Git-Tag: v3.0.35-fsl~1056
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=576f5210e55e7226c67fa143fcc8449409ba713e;p=karo-tx-linux.git

ENGR00178459 mxc_spdif: fix read access for debug info

* Fix read register access for debug info
* Read from spdif registers with a disabled
  spdif core clock leads to kernel hang.
* Avoid it by enabling/diabling core clk.

Signed-off-by: Adrian Alonso <aalonso@freescale.com>
---

diff --git a/sound/soc/codecs/mxc_spdif.c b/sound/soc/codecs/mxc_spdif.c
index 29a5636cb978..26b0af1bdca2 100644
--- a/sound/soc/codecs/mxc_spdif.c
+++ b/sound/soc/codecs/mxc_spdif.c
@@ -81,10 +81,13 @@ struct spdif_mixer_control mxc_spdif_control;
 static unsigned long spdif_base_addr;
 
 #if MXC_SPDIF_DEBUG
-static void dumpregs(void)
+static void dumpregs(struct mxc_spdif_priv *priv)
 {
 	unsigned int value, i;
 
+	if (!priv->tx_active || !priv->rx_active)
+		clk_enable(priv->plat_data->spdif_core_clk);
+
 	for (i = 0 ; i <= 0x38 ; i += 4) {
 		value = readl(spdif_base_addr + i) & 0xffffff;
 		pr_debug("reg 0x%02x = 0x%06x\n", i, value);
@@ -97,9 +100,12 @@ static void dumpregs(void)
 	i = 0x50;
 	value = readl(spdif_base_addr + i) & 0xffffff;
 	pr_debug("reg 0x%02x = 0x%06x\n", i, value);
+
+	if (!priv->tx_active || !priv->rx_active)
+		clk_disable(priv->plat_data->spdif_core_clk);
 }
 #else
-static void dumpregs(void) {}
+static void dumpregs(struct mxc_spdif_priv *priv) {}
 #endif
 
 /* define each spdif interrupt handlers */
@@ -588,7 +594,7 @@ static int mxc_spdif_playback_prepare(struct snd_pcm_substream *substream,
 	regval |= SCR_DMA_TX_EN;
 	__raw_writel(regval, SPDIF_REG_SCR + spdif_base_addr);
 
-	dumpregs();
+	dumpregs(spdif_priv);
 	return 0;
 }
 
@@ -603,7 +609,7 @@ static int mxc_spdif_playback_shutdown(struct snd_pcm_substream *substream,
 	if (!plat_data->spdif_tx)
 		return -EINVAL;
 
-	dumpregs();
+	dumpregs(spdif_priv);
 	pr_debug("SIS: 0x%08x\n", __raw_readl(spdif_base_addr + SPDIF_REG_SIS));
 
 	spdif_intr_status();
@@ -1286,7 +1292,7 @@ static int __devinit mxc_spdif_probe(struct platform_device *pdev)
 		goto card_err;
 	}
 
-	dumpregs();
+	dumpregs(spdif_priv);
 
 	return 0;