RE: [PATCH v3 1/1] scsi: ufs: Enable block layer runtime PM for well-known logical units

[Avri Altman]

> 
> Block layer RPM is enabled for the genernal UFS SCSI devices 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
> a BSG char device via IOCTL may send requests to its corresponding SCSI
> device through its request queue. If BSG IOCTL sends a request to a
> well-known SCSI device when hba is not runtime active, due to block layer
> RPM is not eanbled for the well-known SCSI devices, hba, which is at the
> top of a scsi device's parent chain, shall not be resumed, then unexpected
> error would happen.
> 
> This change enables block layer RPM for the well-known SCSI devices, so
> that block layer can handle RPM for the well-known SCSI devices just like
> for the general SCSI devices.
> 
> Signed-off-by: Can Guo <cang@xxxxxxxxxxxxxx>
Reviewed-by: Avri Altman <avri.altman@xxxxxxx>