ASoC: Don't defer resume work for AC97 codecs
authorMark Brown <broonie@opensource.wolfsonmicro.com>
Tue, 31 Mar 2009 10:27:03 +0000 (11:27 +0100)
committerMark Brown <broonie@opensource.wolfsonmicro.com>
Thu, 2 Apr 2009 15:34:36 +0000 (16:34 +0100)
AC97 devices may have other drivers hanging off them directly so need to
have resumed when the resume function returns meaning that we can't defer
the resume - complete it immediately for them. Non-AC97 devices should
not have other drivers hanging directly off the ASoC devices.

We only really need the deferral for non-AC97 devices - it's there since
some I2C buses are very slow and non-AC97 codecs often have large numbers
of registers to restore and require delays to bring the codec up cleanly
leading to a substantial impact on overall resume time.

Reported-by: Russell King <linux@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
sound/soc/soc-core.c

index 6e710f705a749d5c3162c87cd47793ac68db006f..6c62d4a54cdf9f6c6d1781061adf140059e8347d 100644 (file)
@@ -767,11 +767,21 @@ static int soc_resume(struct platform_device *pdev)
 {
        struct snd_soc_device *socdev = platform_get_drvdata(pdev);
        struct snd_soc_card *card = socdev->card;
+       struct snd_soc_dai *cpu_dai = card->dai_link[0].cpu_dai;
 
-       dev_dbg(socdev->dev, "scheduling resume work\n");
-
-       if (!schedule_work(&card->deferred_resume_work))
-               dev_err(socdev->dev, "resume work item may be lost\n");
+       /* AC97 devices might have other drivers hanging off them so
+        * need to resume immediately.  Other drivers don't have that
+        * problem and may take a substantial amount of time to resume
+        * due to I/O costs and anti-pop so handle them out of line.
+        */
+       if (cpu_dai->ac97_control) {
+               dev_dbg(socdev->dev, "Resuming AC97 immediately\n");
+               soc_resume_deferred(&card->deferred_resume_work);
+       } else {
+               dev_dbg(socdev->dev, "Scheduling resume work\n");
+               if (!schedule_work(&card->deferred_resume_work))
+                       dev_err(socdev->dev, "resume work item may be lost\n");
+       }
 
        return 0;
 }