[alsa-devel] [PATCH] aaci: ARM1176 aaci-pl041 AC97 register read timeout
From: Philby John pjohn@in.mvista.com Date: Tue, 13 Oct 2009 16:30:22 +0530 Subject: [PATCH] aaci: ARM1176 aaci-pl041 AC97 register read timeout
After a reboot on an ARM1176 which amounts to a softreset, it has been noted that the ALSA driver does not get registered and the probe fails with the error "aaci-pl041 fpga:04: ac97 read back fail". In the process of reading from a register the SL1TxBusy bit is set indicating that the transceiver is busy and remains so until the default timeout occurs. Set the Power down register 0x26 to an arbitrary value as specified in the PL041 manual (page: 3-18) so that AACISL1TX/AACISL2TX registers take their default state.
Signed-off-by: Philby John pjohn@in.mvista.com --- sound/arm/aaci.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/sound/arm/aaci.c b/sound/arm/aaci.c index 89096e8..98b6ffe 100644 --- a/sound/arm/aaci.c +++ b/sound/arm/aaci.c @@ -937,6 +937,7 @@ static int __devinit aaci_probe_ac97(struct aaci *aaci) struct snd_ac97 *ac97; int ret;
+ writel(0, aaci->base + AC97_POWERDOWN); /* * Assert AACIRESET for 2us */
At Tue, 13 Oct 2009 19:28:24 +0530, Philby John wrote:
From: Philby John pjohn@in.mvista.com Date: Tue, 13 Oct 2009 16:30:22 +0530 Subject: [PATCH] aaci: ARM1176 aaci-pl041 AC97 register read timeout
After a reboot on an ARM1176 which amounts to a softreset, it has been noted that the ALSA driver does not get registered and the probe fails with the error "aaci-pl041 fpga:04: ac97 read back fail". In the process of reading from a register the SL1TxBusy bit is set indicating that the transceiver is busy and remains so until the default timeout occurs. Set the Power down register 0x26 to an arbitrary value as specified in the PL041 manual (page: 3-18) so that AACISL1TX/AACISL2TX registers take their default state.
Signed-off-by: Philby John pjohn@in.mvista.com
Thanks, applied now.
Takashi
sound/arm/aaci.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/sound/arm/aaci.c b/sound/arm/aaci.c index 89096e8..98b6ffe 100644 --- a/sound/arm/aaci.c +++ b/sound/arm/aaci.c @@ -937,6 +937,7 @@ static int __devinit aaci_probe_ac97(struct aaci *aaci) struct snd_ac97 *ac97; int ret;
- writel(0, aaci->base + AC97_POWERDOWN); /*
*/
- Assert AACIRESET for 2us
-- 1.6.3.3.MVISTA
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participants (2)
-
Philby John -
Takashi Iwai