Messages in this thread | | | Subject | Re: [RFC PATCH 2/5] scsi: ufs: Add UFS-feature layer | From | Bart Van Assche <> | Date | Thu, 11 Jun 2020 21:28:34 -0700 |
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On 2020-06-11 19:27, Daejun Park wrote: >>> @@ -2525,6 +2525,8 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd) >>> >>> ufshcd_comp_scsi_upiu(hba, lrbp); >>> >>> + ufsf_ops_prep_fn(hba, lrbp); >>> + >>> err = ufshcd_map_sg(hba, lrbp); >>> if (err) { >>> lrbp->cmd = NULL; > >> What happens if a SCSI command is retried and hence ufsf_ops_prep_fn() >> is called multiple times for the same SCSI command? > > Developers of UFS features should implement it so that prep_fn does not have > any problems even if it processes the same SCSI command multiple times. > In HPB feature, prep_fn modifies only upiu structure. So it is ok to call > it multiple times because the upiu is rebuilt from ufshcd_comp_scsi_upiu().
Please make sure that this expectation is documented somewhere.
Thanks,
Bart.
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