[alsa-devel] [PATCH v2] ASoC: au1x: PSC-AC97 bugfixes
Manuel Lauss
manuel.lauss at googlemail.com
Tue Sep 8 19:45:17 CEST 2009
This patch fixes the following bugs:
- only reprogram bitdepth if it has changed since last call to hw_params.
- add locking inside ac97_read/write functions:
When reprogramming sample depth, the ac97 unit has to be disabled,
which should not be done in the middle of codec register accesses.
- retry timed-out codec register accesses.
- wait for status bits to set/clear when starting/stopping various
functional blocks; very important after reenabling AC97 unit else
sound may be distorted (e.g. high-pitch noise in 1kHz sine wave).
- clear fifos before/after starting/stopping RX/TX.
- longer timeouts waiting for PSC/AC97 ready after cold reset
with certain codecs this can take ridiculous amounts of time.
Run-tested on various Au1200 platforms with various codecs.
Signed-off-by: Manuel Lauss <manuel.lauss at gmail.com>
---
The previous patch missed a git add for psc.h, sorry!
sound/soc/au1x/psc-ac97.c | 129 +++++++++++++++++++++++++++++++++------------
sound/soc/au1x/psc.h | 1 +
2 files changed, 97 insertions(+), 33 deletions(-)
diff --git a/sound/soc/au1x/psc-ac97.c b/sound/soc/au1x/psc-ac97.c
index 479d7bd..a521aa9 100644
--- a/sound/soc/au1x/psc-ac97.c
+++ b/sound/soc/au1x/psc-ac97.c
@@ -1,8 +1,8 @@
/*
* Au12x0/Au1550 PSC ALSA ASoC audio support.
*
- * (c) 2007-2008 MSC Vertriebsges.m.b.H.,
- * Manuel Lauss <mano at roarinelk.homelinux.net>
+ * (c) 2007-2009 MSC Vertriebsges.m.b.H.,
+ * Manuel Lauss <manuel.lauss at gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -19,6 +19,7 @@
#include <linux/module.h>
#include <linux/device.h>
#include <linux/delay.h>
+#include <linux/mutex.h>
#include <linux/suspend.h>
#include <sound/core.h>
#include <sound/pcm.h>
@@ -29,6 +30,9 @@
#include "psc.h"
+/* how often to retry failed codec register reads/writes */
+#define AC97_RW_RETRIES 5
+
#define AC97_DIR \
(SND_SOC_DAIDIR_PLAYBACK | SND_SOC_DAIDIR_CAPTURE)
@@ -45,6 +49,9 @@
#define AC97PCR_CLRFIFO(stype) \
((stype) == PCM_TX ? PSC_AC97PCR_TC : PSC_AC97PCR_RC)
+#define AC97STAT_BUSY(stype) \
+ ((stype) == PCM_TX ? PSC_AC97STAT_TB : PSC_AC97STAT_RB)
+
/* instance data. There can be only one, MacLeod!!!! */
static struct au1xpsc_audio_data *au1xpsc_ac97_workdata;
@@ -54,24 +61,33 @@ static unsigned short au1xpsc_ac97_read(struct snd_ac97 *ac97,
{
/* FIXME */
struct au1xpsc_audio_data *pscdata = au1xpsc_ac97_workdata;
- unsigned short data, tmo;
+ unsigned short data, retry, tmo;
- au_writel(PSC_AC97CDC_RD | PSC_AC97CDC_INDX(reg), AC97_CDC(pscdata));
+ au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
au_sync();
- tmo = 1000;
- while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)) && --tmo)
- udelay(2);
+ retry = AC97_RW_RETRIES;
+ do {
+ mutex_lock(&pscdata->lock);
+
+ au_writel(PSC_AC97CDC_RD | PSC_AC97CDC_INDX(reg),
+ AC97_CDC(pscdata));
+ au_sync();
+
+ tmo = 2000;
+ while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD))
+ && --tmo)
+ udelay(2);
- if (!tmo)
- data = 0xffff;
- else
data = au_readl(AC97_CDC(pscdata)) & 0xffff;
- au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
- au_sync();
+ au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
+ au_sync();
+
+ mutex_unlock(&pscdata->lock);
+ } while (--retry && !tmo);
- return data;
+ return retry ? data : 0xffff;
}
/* AC97 controller writes to codec register */
@@ -80,16 +96,29 @@ static void au1xpsc_ac97_write(struct snd_ac97 *ac97, unsigned short reg,
{
/* FIXME */
struct au1xpsc_audio_data *pscdata = au1xpsc_ac97_workdata;
- unsigned int tmo;
+ unsigned int tmo, retry;
- au_writel(PSC_AC97CDC_INDX(reg) | (val & 0xffff), AC97_CDC(pscdata));
+ au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
au_sync();
- tmo = 1000;
- while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD)) && --tmo)
+
+ retry = AC97_RW_RETRIES;
+ do {
+ mutex_lock(&pscdata->lock);
+
+ au_writel(PSC_AC97CDC_INDX(reg) | (val & 0xffff),
+ AC97_CDC(pscdata));
au_sync();
- au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
- au_sync();
+ tmo = 2000;
+ while ((!(au_readl(AC97_EVNT(pscdata)) & PSC_AC97EVNT_CD))
+ && --tmo)
+ udelay(2);
+
+ au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
+ au_sync();
+
+ mutex_unlock(&pscdata->lock);
+ } while (--retry && !tmo);
}
/* AC97 controller asserts a warm reset */
@@ -129,9 +158,9 @@ static void au1xpsc_ac97_cold_reset(struct snd_ac97 *ac97)
au_sync();
/* wait for PSC to indicate it's ready */
- i = 100000;
+ i = 1000;
while (!((au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_SR)) && (--i))
- au_sync();
+ msleep(1);
if (i == 0) {
printk(KERN_ERR "au1xpsc-ac97: PSC not ready!\n");
@@ -143,9 +172,9 @@ static void au1xpsc_ac97_cold_reset(struct snd_ac97 *ac97)
au_sync();
/* wait for AC97 core to become ready */
- i = 100000;
+ i = 1000;
while (!((au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)) && (--i))
- au_sync();
+ msleep(1);
if (i == 0)
printk(KERN_ERR "au1xpsc-ac97: AC97 ctrl not ready\n");
}
@@ -165,12 +194,12 @@ static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream,
{
/* FIXME */
struct au1xpsc_audio_data *pscdata = au1xpsc_ac97_workdata;
- unsigned long r, stat;
+ unsigned long r, ro, stat;
int chans, stype = SUBSTREAM_TYPE(substream);
chans = params_channels(params);
- r = au_readl(AC97_CFG(pscdata));
+ r = ro = au_readl(AC97_CFG(pscdata));
stat = au_readl(AC97_STAT(pscdata));
/* already active? */
@@ -180,9 +209,6 @@ static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream,
(pscdata->rate != params_rate(params)))
return -EINVAL;
} else {
- /* disable AC97 device controller first */
- au_writel(r & ~PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
- au_sync();
/* set sample bitdepth: REG[24:21]=(BITS-2)/2 */
r &= ~PSC_AC97CFG_LEN_MASK;
@@ -199,14 +225,40 @@ static int au1xpsc_ac97_hw_params(struct snd_pcm_substream *substream,
r |= PSC_AC97CFG_RXSLOT_ENA(4);
}
- /* finally enable the AC97 controller again */
+ /* do we need to poke the hardware? */
+ if (!(r ^ ro))
+ goto out;
+
+ /* ac97 engine is about to be disabled */
+ mutex_lock(&pscdata->lock);
+
+ /* disable AC97 device controller first... */
+ au_writel(r & ~PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
+ au_sync();
+
+ /* ...wait for it... */
+ while (au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR)
+ asm volatile ("nop");
+
+ /* ...write config... */
+ au_writel(r, AC97_CFG(pscdata));
+ au_sync();
+
+ /* ...enable the AC97 controller again... */
au_writel(r | PSC_AC97CFG_DE_ENABLE, AC97_CFG(pscdata));
au_sync();
+ /* ...and wait for ready bit */
+ while (!(au_readl(AC97_STAT(pscdata)) & PSC_AC97STAT_DR))
+ asm volatile ("nop");
+
+ mutex_unlock(&pscdata->lock);
+
pscdata->cfg = r;
pscdata->rate = params_rate(params);
}
+out:
return 0;
}
@@ -222,6 +274,8 @@ static int au1xpsc_ac97_trigger(struct snd_pcm_substream *substream,
switch (cmd) {
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
+ au_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));
+ au_sync();
au_writel(AC97PCR_START(stype), AC97_PCR(pscdata));
au_sync();
break;
@@ -229,6 +283,13 @@ static int au1xpsc_ac97_trigger(struct snd_pcm_substream *substream,
case SNDRV_PCM_TRIGGER_SUSPEND:
au_writel(AC97PCR_STOP(stype), AC97_PCR(pscdata));
au_sync();
+
+ while (au_readl(AC97_STAT(pscdata)) & AC97STAT_BUSY(stype))
+ asm volatile ("nop");
+
+ au_writel(AC97PCR_CLRFIFO(stype), AC97_PCR(pscdata));
+ au_sync();
+
break;
default:
ret = -EINVAL;
@@ -251,6 +312,8 @@ static int au1xpsc_ac97_probe(struct platform_device *pdev,
if (!au1xpsc_ac97_workdata)
return -ENOMEM;
+ mutex_init(&au1xpsc_ac97_workdata->lock);
+
r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!r) {
ret = -ENODEV;
@@ -269,9 +332,9 @@ static int au1xpsc_ac97_probe(struct platform_device *pdev,
goto out1;
/* configuration: max dma trigger threshold, enable ac97 */
- au1xpsc_ac97_workdata->cfg = PSC_AC97CFG_RT_FIFO8 |
- PSC_AC97CFG_TT_FIFO8 |
- PSC_AC97CFG_DE_ENABLE;
+ au1xpsc_ac97_workdata->cfg = PSC_AC97CFG_RT_FIFO8 |
+ PSC_AC97CFG_TT_FIFO8 |
+ PSC_AC97CFG_DE_ENABLE;
/* preserve PSC clock source set up by platform (dev.platform_data
* is already occupied by soc layer)
@@ -386,4 +449,4 @@ module_exit(au1xpsc_ac97_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Au12x0/Au1550 PSC AC97 ALSA ASoC audio driver");
-MODULE_AUTHOR("Manuel Lauss <mano at roarinelk.homelinux.net>");
+MODULE_AUTHOR("Manuel Lauss <manuel.lauss at gmail.com>");
diff --git a/sound/soc/au1x/psc.h b/sound/soc/au1x/psc.h
index 8fdb1a0..3f474e8 100644
--- a/sound/soc/au1x/psc.h
+++ b/sound/soc/au1x/psc.h
@@ -29,6 +29,7 @@ struct au1xpsc_audio_data {
unsigned long pm[2];
struct resource *ioarea;
+ struct mutex lock;
};
#define PCM_TX 0
--
1.6.4.2
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