RE: [PATCH v2 1/1] scsi: ufs: Enable block layer runtime PM for well-known logical units

From: Avri Altman
Date: Wed Mar 25 2020 - 09:11:55 EST


>
> For the genernal UFS SCSI devices, block layer RPM is enabled for them
> when they are probed by their driver. However block layer RPM is not
> enabled for UFS well-known SCSI devices.
>
> As UFS SCSI devices have their corresponding BSG char devices, accessing
> these BSG char devices may result in sending requests to the SCSI devices
> through their request queues. If BSG IOCTL sends a request to a well-known
> SCSI device when hba is not runtime active, as block layer RPM is not
> eanbled for the well-known SCSI device, hba, which is at the top of its
> parent chain, shall not be resumed, then unexpected error would happen.
While at it, can you fix the ufs-bsg as well?
Add this call to ufs_bsg_probe() and revert commit 74e5e468b664
(scsi: ufs-bsg: Wake the device before sending raw upiu commands) ?

Thanks,
Avri