Re: [patch] snd hda suspend latency: shorten codec read

Takashi Iwai
2007-11-16T14:22:31Z

At Fri, 16 Nov 2007 13:58:24 +0100,
Ingo Molnar wrote:
>
>
> snd hda suspend latency goes down a second via the patch below.
>
> Ingo
>
> ------------->
> Subject: snd hda suspend latency: shorten codec read
> From: Ingo Molnar <mingo@elte.hu>
>
> not sleeping for every codec read/write but doing a short udelay and
> a conditional reschedule has cut suspend+resume latency by about 1
> second on my T60.
>
> Signed-off-by: Ingo Molnar <mingo@elte.hu>

Cute, I applied to ALSA tree now. Thanks!

Takashi

> ---
> sound/pci/hda/hda_intel.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> Index: linux/sound/pci/hda/hda_intel.c
> ===================================================================
> --- linux.orig/sound/pci/hda/hda_intel.c
> +++ linux/sound/pci/hda/hda_intel.c
> @@ -555,7 +555,8 @@ static unsigned int azx_rirb_get_respons
> }
> if (!chip->rirb.cmds)
> return chip->rirb.res; /* the last value */
> - schedule_timeout_uninterruptible(1);
> + udelay(10);
> + cond_resched();
> } while (time_after_eq(timeout, jiffies));
>
> if (chip->msi) {
>