System Hangs while suspending

Srinivas Marakala1

Other Parts Discussed in Thread: AM3356

Hi,

We have custom platform based on AM3356. During suspend (echo mem > /sys/power/state), it hangs while going through mmc0 device suspend (mmcblk). We have SD Card connected on mmc0 which we are using as boot up media. It hangs in dpm_run_callback. If I comment out error = cb(dev), I do not see hang and system suspends fine.

I guess cb(dev), ultimately calls suspend function 'mmc_blk_suspend' defined in block.c file. If I simply return from this function also, still hang is there. But If I comment out 'error=cb(dev)', I see no issue.

Hang does not happens all the time. We added "uim-sysfs" start service to Init scripts to start uim-sysfs service on boot. If this service is started as part of Init scripts, I see suspend hang. If I remove the service from Init scrips,a nd run it manually, I do not see suspend hang when I try to suspend the platform. Platform is a headless device and we will have to run in house built application. If I try to run this application also, I see suspend hang issues.

We are using Linux 3.12.10. TI release 7.00.00 for AM335x family.

I am confused on what causing this mmc0 sleep hang. Any help is highly appreciated.

Thanks,

Srinivas

over 11 years ago

0 Srinivas Marakala1 over 11 years ago

Intellectual 560 points

On further debugging I found that it hangs in __mmc_claim_host (called from sd driver suspend). Looks like some one else claimed the host, and not released. And while suspending, it wait to claim for Host in while loop. Any such known issues?

Thanks,

Srinivas

0 Biser Gatchev-XID over 11 years ago in reply to Srinivas Marakala1

TI__Guru**** 393215 points

Hi Srinivas,

The attached guide gives some tips for debugging suspend/resume issues: 8867.sitara_boot_camp_am335x_pm_sw_training.pdf

0 Srinivas Marakala1 over 11 years ago in reply to Biser Gatchev-XID

Intellectual 560 points

Thanks for the document Biser. It is a very useful document.

I have a slightly different scenario here. Some driver or user space app claimed the mmc host bus and not released it yet. At this instance mmc SD driver sleep sequence is also trying to claim the bus before it tries to put it to sleep. It is not getting the bus control and it waits there itself.

Probably still some user space application is running and leading to this issue. I will figure out who is holding the bus during this failure case.

Thanks,

Srinivas

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System Hangs while suspending