Re: [RESEND PATCH] scsi: ufs: fix race between clock gating and devfreq scaling work

From: Martin K. Petersen
Date: Fri Oct 14 2016 - 16:48:51 EST

>>>>> "Subhash" == Subhash Jadavani <subhashj@xxxxxxxxxxxxxx> writes:

Subhash> UFS devfreq clock scaling work may require clocks to be ON if
Subhash> it need to execute some UFS commands hence it may request for
Subhash> clock hold before issuing the command. But if UFS clock gating
Subhash> work is already running in parallel, ungate work would end up
Subhash> waiting for the clock gating work to finish and as clock gating
Subhash> work would also wait for the clock scaling work to finish, we
Subhash> would enter in deadlock state. Here is the call trace during
Subhash> this deadlock state:

Somebody from the UFS camp, please review!

Martin K. Petersen Oracle Linux Engineering