[alsa-devel] [PATCH] ASoC: Writing register default value for the reset register
The WM8983 can be reset by performing a write of any value to the software reset register. To avoid writing to the software reset register while resume, we should write the same value in wm8983_reg_defs to software reset register in wm8983_probe(). The write to the reset register is suppressed by the cache restore code when it skips writes of default registers.
Signed-off-by: Axel Lin axel.lin@gmail.com --- sound/soc/codecs/wm8983.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/sound/soc/codecs/wm8983.c b/sound/soc/codecs/wm8983.c index 17f04ec..93ee284 100644 --- a/sound/soc/codecs/wm8983.c +++ b/sound/soc/codecs/wm8983.c @@ -1007,7 +1007,7 @@ static int wm8983_probe(struct snd_soc_codec *codec) return ret; }
- ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0x8983); + ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0); if (ret < 0) { dev_err(codec->dev, "Failed to issue reset: %d\n", ret); return ret;
On Tue, Oct 11, 2011 at 05:55:00PM +0800, Axel Lin wrote:
The WM8983 can be reset by performing a write of any value to the software reset register. To avoid writing to the software reset register while resume, we should write the same value in wm8983_reg_defs to software reset register in wm8983_probe(). The write to the reset register is suppressed by the cache restore code when it skips writes of default registers.
Signed-off-by: Axel Lin axel.lin@gmail.com
sound/soc/codecs/wm8983.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/sound/soc/codecs/wm8983.c b/sound/soc/codecs/wm8983.c index 17f04ec..93ee284 100644 --- a/sound/soc/codecs/wm8983.c +++ b/sound/soc/codecs/wm8983.c @@ -1007,7 +1007,7 @@ static int wm8983_probe(struct snd_soc_codec *codec) return ret; }
- ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0x8983);
- ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0); if (ret < 0) { dev_err(codec->dev, "Failed to issue reset: %d\n", ret); return ret;
We should probably just handle the reset register specially during resume.
Thanks, Dimitris
On Tue, Oct 11, 2011 at 01:33:05PM +0100, Dimitris Papastamos wrote:
On Tue, Oct 11, 2011 at 05:55:00PM +0800, Axel Lin wrote:
The WM8983 can be reset by performing a write of any value to the software reset register.
- ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0x8983);
- ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0);
We should probably just handle the reset register specially during resume.
I really don't think it's worth the code complexity to add special handling like that, this is a trivial patch which avoids the need for any extra infrastructure.
On Tue, Oct 11, 2011 at 02:31:18PM +0100, Mark Brown wrote:
On Tue, Oct 11, 2011 at 01:33:05PM +0100, Dimitris Papastamos wrote:
On Tue, Oct 11, 2011 at 05:55:00PM +0800, Axel Lin wrote:
The WM8983 can be reset by performing a write of any value to the software reset register.
- ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0x8983);
- ret = snd_soc_write(codec, WM8983_SOFTWARE_RESET, 0);
We should probably just handle the reset register specially during resume.
I really don't think it's worth the code complexity to add special handling like that, this is a trivial patch which avoids the need for any extra infrastructure.
Aw I thought this code was using the old style open coded syncing functions, which would be trivial and perhaps idiomatic to simply check for the reset register and continue.
Thanks, Dimitris
participants (3)
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Axel Lin -
Dimitris Papastamos -
Mark Brown