Hi Ryan!
Just some questions inline - in general I like the reset function.
On Mon, Nov 26, 2018 at 10:46 AM Ryan Lee <RyanS.Lee@xxxxxxxxxxxxxxxxxxx> wrote:
>
> Signed-off-by: Ryan Lee <ryans.lee@xxxxxxxxxxxxxxxxxxx>
> ---
> Changes : Created max98373_reset function to minimize code duplication.
> Changed regmap_write to regmap_update_bits. Other bits except LSB need to be masked.
> Added reset verification step to make sure software reset is completed well. Software reset is done in 10ms in normal case.
> Revision ID is available when the amp is in the idle state which means software reset is completed.
> Software reset will be performed maximum 3 times to avoid amp reset failure. Generally it is done in the first trial.
> sleep time after software reset is increased + 30ms for every retrial. Maximum possible msleep time is 100 ms (initial 10 ms + 30 ms * 3 times).
Why is the sleep time increased after each SW reset?
What is the failure case that you've seen which would benefit from this?
>
> sound/soc/codecs/max98373.c | 41 +++++++++++++++++++++++++++++++++++------
> 1 file changed, 35 insertions(+), 6 deletions(-)
>
> diff --git a/sound/soc/codecs/max98373.c b/sound/soc/codecs/max98373.c
> index a09d013..55af7f02 100644
> --- a/sound/soc/codecs/max98373.c
> +++ b/sound/soc/codecs/max98373.c
> @@ -724,14 +724,45 @@ static struct snd_soc_dai_driver max98373_dai[] = {
> }
> };
>
> +static void max98373_reset(struct max98373_priv *max98373, struct device *dev)
> +{
> + int ret, reg, count, delay;
> +
> + count = 0;
> + while (true) {
> + /* Software Reset */
> + ret = regmap_update_bits(max98373->regmap,
> + MAX98373_R2000_SW_RESET,
> + MAX98373_SOFT_RESET,
> + MAX98373_SOFT_RESET);
> + if (ret)
> + dev_err(dev, "Reset command failed. (ret:%d)\n", ret);
> +
> + delay = 10000 + (count * 30000);
> + usleep_range(delay, delay + 1000);
> +
> + /* Software Reset Verification */
> + ret = regmap_read(max98373->regmap,
> + MAX98373_R21FF_REV_ID, ®);
> + if (!ret) {
> + dev_info(dev, "Reset completed (retry:%d)\n", count);
> + break;
Instead of break, can the code return here?
"break" implies something else will happen after the while loop exits
- there isn't.
> + }
> +
> + if (++count > 3) {
> + dev_err(dev, "Reset failed. (ret:%d)\n", ret);
> + break;
> + }
> + usleep_range(10000, 11000);
Why is there a second delay after reading MAX98373_R21FF_REV_ID?
Is this really necessary?
If the second usleep_range() isn't needed, it would be better/clearer
to make code loop on "while (count < 4)". And then outside the while
loop, use dev_err() to share what the failure was.
> + }
> +}
> +
> static int max98373_probe(struct snd_soc_component *component)
> {
> struct max98373_priv *max98373 = snd_soc_component_get_drvdata(component);
>
> /* Software Reset */
> - regmap_write(max98373->regmap,
> - MAX98373_R2000_SW_RESET, MAX98373_SOFT_RESET);
> - usleep_range(10000, 11000);
> + max98373_reset(max98373, component->dev);
>
> /* IV default slot configuration */
> regmap_write(max98373->regmap,
> @@ -818,9 +849,7 @@ static int max98373_resume(struct device *dev)
> {
> struct max98373_priv *max98373 = dev_get_drvdata(dev);
>
> - regmap_write(max98373->regmap,
> - MAX98373_R2000_SW_RESET, MAX98373_SOFT_RESET);
> - usleep_range(10000, 11000);
> + max98373_reset(max98373, dev);
> regcache_cache_only(max98373->regmap, false);
> regcache_sync(max98373->regmap);
> return 0;
> --
> 2.7.4
>
cheers,
grant
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
