On Sat, Jun 29, 2024 at 05:09:54AM +0200, Niklas Cassel wrote: > On Fri, Jun 28, 2024 at 11:31:35PM +0000, Igor Pylypiv wrote: > > On Fri, Jun 28, 2024 at 08:44:41PM +0200, Niklas Cassel wrote: > > > On Thu, Jun 27, 2024 at 09:54:06PM +0000, Igor Pylypiv wrote: > > > > > > > > Thank you, Niklas! I agree that this code is too complicated and should be > > > > simplified. I don't think we should change the code too much in this patch > > > > since it is going to be backported to stable releases. > > > > > > > > Would you mind sending a patch for the proposed simplifications following > > > > this patch series? > > > > > > > > > > I would prefer if we changed it as part of this commit to be honest. > > > > > > > > > I also re-read the SAT spec, and found that it says that: > > > """ > > > If the CK_COND bit is set to: > > > a) one, then the SATL shall return a status of CHECK CONDITION upon ATA command completion, > > > without interpreting the contents of the STATUS field and returning the ATA fields from the request > > > completion in the sense data as specified in table 209; and > > > b) zero, then the SATL shall terminate the command with CHECK CONDITION status only if an error > > > occurs in processing the command. See clause 11 for a description of ATA error conditions. > > > """ > > > > > > So it seems quite clear that if CK_COND == 1, we should set CHECK CONDITION, > > > so that answers the question/uncertainty I asked/expressed in earlier emails. > > > > > > > > > I think this patch (which should be applied on top of your v3 series), > > > makes the code way easier to read/understand: > > > > > > > Agree, having self-explanatory variable names makes the code much more > > readable. I'll add the patch in v4. > > > > Do you mind if I set you as the author of the patch with the corresponding > > Signed-off-by tag? > > I still think that you are the author. > > But if you want, feel free to add me as: Co-developed-by > (which would also require you to add my Signed-off-by), see: > https://www.kernel.org/doc/html/latest/process/submitting-patches.html#when-to-use-acked-by-cc-and-co-developed-by > Sounds good! Added the Co-developed-by abd Signed-off-by tags in v4. Thanks! > > > > > > diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c > > > index d5874d4b9253..5b211551ac10 100644 > > > --- a/drivers/ata/libata-scsi.c > > > +++ b/drivers/ata/libata-scsi.c > > > @@ -1659,26 +1656,27 @@ static void ata_scsi_qc_complete(struct ata_queued_cmd *qc) > > > { > > > struct scsi_cmnd *cmd = qc->scsicmd; > > > u8 *cdb = cmd->cmnd; > > > - int need_sense = (qc->err_mask != 0) && > > > - !(qc->flags & ATA_QCFLAG_SENSE_VALID); > > > - int need_passthru_sense = (qc->err_mask != 0) || > > > - (qc->flags & ATA_QCFLAG_SENSE_VALID); > > > + bool have_sense = qc->flags & ATA_QCFLAG_SENSE_VALID; > > > + bool is_ata_passthru = cdb[0] == ATA_16 || cdb[0] == ATA_12; > > > + bool is_ck_cond_request = cdb[2] & 0x20; > > > + bool is_error = qc->err_mask != 0; > > > > > > /* For ATA pass thru (SAT) commands, generate a sense block if > > > * user mandated it or if there's an error. Note that if we > > > - * generate because the user forced us to [CK_COND =1], a check > > > + * generate because the user forced us to [CK_COND=1], a check > > > * condition is generated and the ATA register values are returned > > > * whether the command completed successfully or not. If there > > > - * was no error, we use the following sense data: > > > + * was no error, and CK_COND=1, we use the following sense data: > > > * sk = RECOVERED ERROR > > > * asc,ascq = ATA PASS-THROUGH INFORMATION AVAILABLE > > > */ > > > - if (((cdb[0] == ATA_16) || (cdb[0] == ATA_12)) && > > > - ((cdb[2] & 0x20) || need_passthru_sense)) { > > > - if (!(qc->flags & ATA_QCFLAG_SENSE_VALID)) > > > + if (is_ata_passthru && (is_ck_cond_request || is_error || have_sense)) { > > > + if (!have_sense) > > > ata_gen_passthru_sense(qc); > > > ata_scsi_set_passthru_sense_fields(qc); > > > - } else if (need_sense) { > > > + if (is_ck_cond_request) > > > + set_status_byte(qc->scsicmd, SAM_STAT_CHECK_CONDITION); > > > > SAM_STAT_CHECK_CONDITION will be set by ata_gen_passthru_sense(). Perhaps we > > can move the SAM_STAT_CHECK_CONDITION setting into else if? > > I think it is fine that: > if (is_ck_cond_request) > set_status_byte(qc->scsicmd, SAM_STAT_CHECK_CONDITION); > > might set SAM_STAT_CHECK_CONDITION even if it is already set. > > Personally, I think that my suggestion is slightly clearer when it comes > to highlight the behavior of CK_COND. (CK_COND will set CHECK_CONDITION, > regardless if successful command or error command, and regardless if > we already had sense or not.) > > And considering that we finally make this hard to read code slightly more > readable than it was to start off with, I would prefer my alternative. > It makes senes. Added the patch in v4. Thank you! > > Kind regards, > Niklas
