ALSA: ad1889: Replace mdelay with usleep_range in snd_ad1889_ac97_ready

snd_ad1889_ac97_ready() is never called in atomic context.

The call chain ending up at snd_ad1889_ac97_ready() is:
[1] snd_ad1889_ac97_ready() <- snd_ad1889_ac97_xinit() <-
	snd_ad1889_ac97_init() <- snd_ad1889_probe()

snd_ad1889_probe() is only set as ".probe" in struct pci_driver.
This function is not called in atomic context.

Despite never getting called from atomic context, snd_ad1889_ac97_ready()
calls mdelay for busy wait.
This is not necessary and can be replaced with usleep_range to
avoid busy waiting.

This is found by a static analysis tool named DCNS written by myself.

Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/ad1889.c b/sound/pci/ad1889.c
index d4965ebe967f8fc705f8f0f7807ac19e1191716a..d9c54c08e2dbde1e46421dd42f5647f57e329590 100644 (file)
--- a/sound/pci/ad1889.c
+++ b/sound/pci/ad1889.c
@@ -258,7 +258,7 @@ snd_ad1889_ac97_ready(struct snd_ad1889 *chip)
        
        while (!(ad1889_readw(chip, AD_AC97_ACIC) & AD_AC97_ACIC_ACRDY) 
                        && --retry)
-               mdelay(1);
+               usleep_range(1000, 2000);
        if (!retry) {
                dev_err(chip->card->dev, "[%s] Link is not ready.\n",
                        __func__);