At Tue, 21 Apr 2015 11:58:54 +0200, Gabriele Mazzotta wrote:
2015-04-19 19:26 GMT+02:00 Gabriele Mazzotta gabriele.mzt@gmail.com:
Hi,
I've recently found that commit a551d91473 ("ALSA: hda - Use regmap for command verb caches, too") is somehow causing a pop noise on startup when headphones are plugged in, but I couldn't figure out the exact cause. Was this observed on other systems (mine is a Dell XPS13 9333, Realtek ALC3661)? Does anyone have any idea of what the cause might be?
Small update: I found that if I add a printk in alc_shutup_dell_xps13() or I increase the delay from 20ms to 200ms, I get the pop noise on start, with or without a551d91473 reverted. I will try to find out what this delay is exactly affecting.
Interesting. I didn't think that increasing the delay affects (not decreasing).
Maybe you'd be better to trace the verbs that are issued around the headphone jack plugging. The tracepoints are your friend. See HD-audio.txt for a brief instruction.
thanks,
Takashi