By the way, while looking at the current mce_down code:

http://hg.alsa-project.org/alsa-kernel/file/0028e39ead78/isa/ad1848/ad1848_l... http://hg.alsa-project.org/alsa-kernel/file/0028e39ead78/isa/cs423x/cs4231_l...

we have the ad1848 loops doing:

end_time = jiffies + msecs_to_jiffies(250); while (snd_ad1848_in(chip, AD1848_TEST_INIT) & AD1848_CALIB_IN_PROGRESS) { spin_unlock_irqrestore(&chip->reg_lock, flags); (---) if (time_after(jiffies, end_time)) { snd_printk(KERN_ERR " [ timeout ] ") return; } msleep(1); spin_lock_irqsave(&chip->reg_lock, flags); }

At (---) we are no longer atomic, so imagine being pre-empted there. When we get back, we may/will well be past end_time and although by now calibration has long finished, we bail out believing we've timed out.

Should it rather be this (probably with a "goto eror" type of setup, but as far as the logic is concerned)?

end_time = jiffies + msecs_to_jiffies(250); while (snd_ad1848_in(chip, AD1848_TEST_INIT) & AD1848_CALIB_IN_PROGRESS) { if (time_after(jiffies, end_time)) { spin_unlock_irqrestore(&chip->reg_lock, flags); snd_printk(KERN_ERR " [ timeout ] ") return; } spin_unlock_irqrestore(&chip->reg_lock, flags); msleep(1); spin_lock_irqsave(&chip->reg_lock, flags); }

Moreover, we aren't under lock at all in the cs4231 version (which also means that msleep(1) thing is in fact fine there). Can't we do that for ad1848 as well?

(but as said, minimal fix for now is the msleep(1) under lock fix in ad1848)

Rene.