On 9/15/21 8:35 AM, Adrian Hunter wrote:
Thanks for the idea. Unfortunately it does not work for pass-through requests, refer scsi_noretry_cmd(). sdev_ufs_device and sdev_rpmb are used with pass-through requests.
How about allocating and submitting the REQUEST SENSE command from the context of a workqueue, or in other words, switching back to scsi_execute()? Although that approach doesn't guarantee that the unit attention condition is cleared before the first SCSI command is received from outside the UFS driver, I don't see any other solution since my understanding is that the deadlock between blk_mq_freeze_queue() and blk_get_request() from inside ufshcd_err_handler() can also happen without "ufs: Synchronize SCSI and UFS error handling". The only code I know of that relies on the UFS driver clearing unit attentions is this code: https://android.googlesource.com/platform/system/core/+/master/trusty/storage/proxy/rpmb.c The code that submits a REQUEST SENSE was added in the UFS driver as the result of a request from the team that maintains the Trusty code. Earlier today I have been promised that unit attention handling support will be added in Trusty but I do not when this will be realized. Bart.
