hda_intel suspend latency: shorten codec read

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.

The patch also fixes the unexpected codec-connection errors that
happen more often in the new power-save mode:
    http://lkml.org/lkml/2007/11/8/255
    http://bugzilla.kernel.org/show_bug.cgi?id=9332

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
index 3fa0f97..62b9fb3 100644 (file)
--- a/sound/pci/hda/hda_intel.c
+++ b/sound/pci/hda/hda_intel.c
@@ -555,7 +555,8 @@ static unsigned int azx_rirb_get_response(struct hda_codec *codec)
                }
                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) {