Hi,
on my battery-based i.MX28 board with SGTL5000 codec and kernel 2.6.35.3 I change the cpu frequency on the fly (for powersave purposes).
The used soundsystem is ALSA.
All works fine and I can play any wave file with "aplay".
But if the CPU frequency changes while "aplay" is playing, sometimes "aplay" stops.
In this case the status of the "aplay" process is S (sleeping).
To change the CPU frequency I use the follwoing commands:
echo performance > /sys/devices/system/cpu/cpu0/scaling_governor
echo powersave > /sys/devices/system/cpu/cpu0/scaling_governor
Any idea?
Regards
Toni
已解决! 转到解答。
Hi Saurabh,
i'm trying to port mx28 cpufreq support into Linux mainline. It would be interesting to know if the problem still occur in a current kernel version.
Unfortunately i don't a mx28 board with audio interface to test it.
Maybe you want to give it a try:
https://github.com/lategoodbye/linux-mxs-power
Stefan
Hi Saurabh,
do you have the same problem?
Could you explain the problem a little more:
Does aplay stops forever after change frequency or does it hangs only a random amount of time?
Stefan
Hi,
Stefan
We are getting system crash issue while playing short track 15ms vector in loopback mode.
[<802bc274>] (snd_pcm_period_elapsed+0x44/0xd8) from [<801a336c>] (sdma_tasklet+0x90/0x134)
[<801a336c>] (sdma_tasklet+0x90/0x134) from [<80029b00>] (tasklet_action+0x98/0xfc)
[<80029b00>] (tasklet_action+0x98/0xfc) from [<80029240>] (__do_softirq+0xd4/0x1c0)
[<80029240>] (__do_softirq+0xd4/0x1c0) from [<800293b4>] (do_softirq+0x44/0x50)
So I am trying to possible root cause behind this issue.
Saurabh
Hi Saurabh,
i'm trying to port mx28 cpufreq support into Linux mainline. It would be interesting to know if the problem still occur in a current kernel version.
Unfortunately i don't a mx28 board with audio interface to test it.
Maybe you want to give it a try:
https://github.com/lategoodbye/linux-mxs-power
Stefan