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authorRussell King <rmk+kernel@arm.linux.org.uk>2011-02-05 10:41:55 +0000
committerRussell King <rmk+kernel@arm.linux.org.uk>2011-02-07 15:15:26 +0000
commit7c289385b84d136089b8a1149321ebffa5193595 (patch)
tree2d591872a86dfa7f042371501d014e54e3ecda50
parentec11594fbd5a3d2a47a7a7eda6d076363b78957c (diff)
downloadop-kernel-dev-7c289385b84d136089b8a1149321ebffa5193595.zip
op-kernel-dev-7c289385b84d136089b8a1149321ebffa5193595.tar.gz
ALSA: AACI: allow writes to MAINCR to take effect
The AACI TRM requires the MAINCR enable bit to be held zero for two bitclk cycles plus three apb_pclk cycles. Use a delay of 1us to ensure this. Ensure that writes to MAINCR to change the addressed codec only happen when required, and that they take effect in a similar manner to the above, otherwise we seem to occasionally have stuck slot busy bits. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
-rw-r--r--sound/arm/aaci.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/sound/arm/aaci.c b/sound/arm/aaci.c
index 24d3013..7c1fc64 100644
--- a/sound/arm/aaci.c
+++ b/sound/arm/aaci.c
@@ -50,7 +50,11 @@ static void aaci_ac97_select_codec(struct aaci *aaci, struct snd_ac97 *ac97)
if (v & SLFR_1RXV)
readl(aaci->base + AACI_SL1RX);
- writel(maincr, aaci->base + AACI_MAINCR);
+ if (maincr != readl(aaci->base + AACI_MAINCR)) {
+ writel(maincr, aaci->base + AACI_MAINCR);
+ readl(aaci->base + AACI_MAINCR);
+ udelay(1);
+ }
}
/*
@@ -993,6 +997,8 @@ static unsigned int __devinit aaci_size_fifo(struct aaci *aaci)
* disabling the channel doesn't clear the FIFO.
*/
writel(aaci->maincr & ~MAINCR_IE, aaci->base + AACI_MAINCR);
+ readl(aaci->base + AACI_MAINCR);
+ udelay(1);
writel(aaci->maincr, aaci->base + AACI_MAINCR);
/*
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