[alsa-devel] Not able to restart audio after hibernation
Hello Mark,
I am testing my audio driver on spear platform with the linux kernel 2.6.37. During testing I put my system in hibernation mode and found that there is no sound after resume. The steps I am using for hibernation are 1. Have audio player on, select some audio, (using aplay utils) 2. Hibernate machine 3. Resume from hibernate
After resume it seems that there is no data available in the buffer to play, as application is giving pcm_write error and exit.
While going through the suspend/resume implementation in the alsa framework, get to know that feature to support hibernation is missing. The suspend/resume implementation for audio is with dev_pm_ops which is present in snd-core.c . If we look into the structure, we have only suspend, resume and poweroff feature present in it. To support hibernation we need freeze,thaw and restore also. Please correct me if I am wrong?
Just for experiment I modified the structure and added freeze, thaw and restore functionality, but the result is same. The new modified structure looks like
static const struct dev_pm_ops soc_pm_ops = { .suspend = soc_suspend, .resume = soc_resume, .freeze = soc_suspend, .thaw = soc_resume, .restore = soc_resume,
.poweroff = soc_poweroff, }
Just for info audio is working fine in case of suspend-to-ram.
Best Regards ~Rajeev
On Fri, Jan 06, 2012 at 04:17:50PM +0530, Rajeev kumar wrote:
While going through the suspend/resume implementation in the alsa framework, get to know that feature to support hibernation is missing.
Hibernation is not supported on ARM at all. Is SPEAR not an ARM based platform?
Just for experiment I modified the structure and added freeze, thaw and restore functionality, but the result is same. The new modified structure looks like
This suggests that you have a bug in your suspend and resume implementation, possibly outside of this driver.
On Fri, 2012-01-06 at 10:32 -0800, Mark Brown wrote:
On Fri, Jan 06, 2012 at 04:17:50PM +0530, Rajeev kumar wrote:
While going through the suspend/resume implementation in the alsa framework, get to know that feature to support hibernation is missing.
Hibernation is not supported on ARM at all. Is SPEAR not an ARM based platform?
It isn't? Hibernate is supported on all systems to some level. Essentially the cpu is just halting all threads and saving state (cpu, memory, and device configs) to storage.
And I have a couple of arm development platforms here that would beg to argue with this statement.
On Fri, Jan 06, 2012 at 12:54:33PM -0800, Tobin Davis wrote:
On Fri, 2012-01-06 at 10:32 -0800, Mark Brown wrote:
Hibernation is not supported on ARM at all. Is SPEAR not an ARM based platform?
It isn't? Hibernate is supported on all systems to some level. Essentially the cpu is just halting all threads and saving state (cpu, memory, and device configs) to storage.
...and then restoring it later when we power on again. It's this bit that had been tricky.
And I have a couple of arm development platforms here that would beg to argue with this statement.
Perhaps it's been supported since I last looked, but if it has there's a *lot* of drivers for ARM based systems which need to be updated.
participants (3)
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Mark Brown -
Rajeev kumar -
Tobin Davis