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ARM: pxa27x: fix ac97 controller warm reset code

PATCH New Mike Dunn 3 participants 5 messages Dec 28, 2012

Subsystems (3)
Arm (32-bit) Arm sub-architectures PXA2xx/PXA3xx support
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Mike Dunn

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#0 lore raw

PATCH 1/1 ARM: pxa27x: fix ac97 controller warm reset code

This patch fixes some code that implements a work-around to a hardware bug in the ac97 controller on the pxa27x. A bug in the controller's warm reset functionality requires that the mfp used by the controller as the AC97_RESET_n line be temporarily reconfigured as a generic output gpio (AF0) and manually held high for the duration of the warm reset cycle. This is what was done in the original code, but it was broken long ago by commit fb1bf8cd13bfa7ed0364ab0d82f717fc020d35f6, which changed the mfp to a GPIO input instead of a high output.

Signed-off-by Mike Dunn <[email protected]>
---
 arch/arm/mach-pxa/pxa27x.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
arch/arm/mach-pxa/pxa27x.c +2 -2
index 8047ee0..76221e4 100644
@@ -47,9 +47,9 @@ void pxa27x_clear_otgph(void)
 EXPORT_SYMBOL(pxa27x_clear_otgph);
 
 static unsigned long ac97_reset_config[] = {
-	GPIO113_GPIO,
+	MFP_CFG_OUT(GPIO113, AF0, DRIVE_HIGH),
 	GPIO113_AC97_nRESET,
-	GPIO95_GPIO,
+	MFP_CFG_OUT(GPIO95, AF0, DRIVE_HIGH),
 	GPIO95_AC97_nRESET,
 };

--
1.7.8.6

maintainer
#1 lore raw

PATCH 1/1 ARM: pxa27x: fix ac97 controller warm reset code

Quoted 10 lines · Mike Dunn

This patch fixes some code that implements a work-around to a hardware bug in the ac97 controller on the pxa27x. A bug in the controller's warm reset functionality requires that the mfp used by the controller as the AC97_RESET_n line be temporarily reconfigured as a generic output gpio (AF0) and manually held high for the duration of the warm reset cycle. This is what was done in the original code, but it was broken long ago by commit fb1bf8cd13bfa7ed0364ab0d82f717fc020d35f6, which changed the mfp to a GPIO input instead of a high output.

Signed-off-by Mike Dunn <[email protected]>
Acked-by Robert Jarzmik <[email protected]>

As a side note, shouldn't this patch (as the other one on ALSA), once reviewed, be submitted to stable kernel ?

Cheers.

Signature · 1 line
Robert
author
#2 lore raw

PATCH 1/1 ARM: pxa27x: fix ac97 controller warm reset code

Hi Roert, thanks again.

Quoted 11 lines · Robert Jarzmik
Quoted 9 lines · Mike Dunn

This patch fixes some code that implements a work-around to a hardware bug in the ac97 controller on the pxa27x. A bug in the controller's warm reset functionality requires that the mfp used by the controller as the AC97_RESET_n line be temporarily reconfigured as a generic output gpio (AF0) and manually held high for the duration of the warm reset cycle. This is what was done in the original code, but it was broken long ago by commit fb1bf8cd13bfa7ed0364ab0d82f717fc020d35f6, which changed the mfp to a GPIO input instead of a high output.

Quoted 6 lines
Quoted 1 line
Signed-off-by Mike Dunn <[email protected]>
Acked-by Robert Jarzmik <[email protected]>

As a side note, shouldn't this patch (as the other one on ALSA), once reviewed, be submitted to stable kernel ?

Dunno. I'm kind of a newbie. If the stable tree is for urgent fixes, well, these have been broken for a long time.

Happy New Year!

Mike

#3 lore raw

PATCH 1/1 ARM: pxa27x: fix ac97 controller warm reset code

In reply to Mike Dunn

Hello.

Quoted 7 lines · Mike Dunn

This patch fixes some code that implements a work-around to a hardware bug in the ac97 controller on the pxa27x. A bug in the controller's warm reset functionality requires that the mfp used by the controller as the AC97_RESET_n line be temporarily reconfigured as a generic output gpio (AF0) and manually held high for the duration of the warm reset cycle. This is what was done in the original code, but it was broken long ago by commit fb1bf8cd13bfa7ed0364ab0d82f717fc020d35f6, which changed the mfp to a GPIO input

Please also specify the summary of that commit in parens.

Quoted 3 lines

instead of a high output.

Signed-off-by Mike Dunn <[email protected]>

WBR, Sergei

author
#4 lore raw

PATCH 1/1 ARM: pxa27x: fix ac97 controller warm reset code

Quoted 12 lines · Sergei Shtylyov

Hello.

Quoted 7 lines · Mike Dunn

This patch fixes some code that implements a work-around to a hardware bug in the ac97 controller on the pxa27x. A bug in the controller's warm reset functionality requires that the mfp used by the controller as the AC97_RESET_n line be temporarily reconfigured as a generic output gpio (AF0) and manually held high for the duration of the warm reset cycle. This is what was done in the original code, but it was broken long ago by commit fb1bf8cd13bfa7ed0364ab0d82f717fc020d35f6, which changed the mfp to a GPIO input

Quoted 1 line

Please also specify the summary of that commit in parens.

OK, will resend patch.

Thanks,
Mike