RE: [PATCH] ASoC: max98373: Added 10ms delay after amp software reset

From: Ryan Lee
Date: Thu Aug 23 2018 - 21:05:30 EST


>-----Original Message-----
>From: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
>Sent: Thursday, August 23, 2018 5:08 PM
>To: Mark Brown <broonie@xxxxxxxxxx>
>Cc: Ryan Lee <RyanS.Lee@xxxxxxxxxxxxxxxxxxx>; Liam Girdwood
><lgirdwood@xxxxxxxxx>; Jaroslav Kysela <perex@xxxxxxxx>; Takashi Iwai
><tiwai@xxxxxxxx>; Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>;
>alsa-devel@xxxxxxxxxxxxxxxx; lkml <linux-kernel@xxxxxxxxxxxxxxx>;
>ryan.lee.maxim@xxxxxxxxx
>Subject: Re: [PATCH] ASoC: max98373: Added 10ms delay after amp software
>reset
>
>EXTERNAL EMAIL
>
>
>
>On Thu, Aug 23, 2018 at 10:51:07AM +0100, Mark Brown wrote:
>> On Wed, Aug 22, 2018 at 05:31:04PM -0700, Dmitry Torokhov wrote:
>> > On Wed, Aug 22, 2018 at 5:21 PM Ryan Lee
><ryans.lee@xxxxxxxxxxxxxxxxxxx> wrote:
>> > > + mdelay(10);
>>
>> > Is it really necessary for the CPU to spin for 10msec here?
>> > usleep_range() would be better solution.
>>
>> Or msleep() for that matter, it's not going ot be the end of the world
>> if we delay a bit too long.
>
>Frankly, I'd rather we did not introduce extra delays. I do not know if we use
>this part, but on ChromeOS we are interested in shaving as much from the boot
>time as possible and 10 msecs here and 10 msecs there do add up.

Thanks for all your feedback.
Let me apply usleep_range() or msleep() instead of using mdelay().

>
>Thanks.
>
>--
>Dmitry