Ming, > request with scsi_cmnd may be allocated by the ufshpb driver, even it > should be fine to call ufshcd_queuecommand() directly for this driver > private IO, if the tag can be reused. One example is scsi_ioctl_reset(). scsi_ioctl_reset() allocates a new request, though, so that doesn't solve the forward progress guarantee. Whereas eh puts the saved request on the stack. -- Martin K. Petersen Oracle Linux Engineering