On Wed, 2012-05-16 at 16:41 -0700, Nicholas A. Bellinger wrote:
> On Wed, 2012-05-16 at 13:33 +0800, mengcong wrote:
> > The cdrecord uses ATA_PASS_THROUGH_16 command while burning CDs
> > with a SATA CD-ROM. This patch adds support to it so that PSCSI
> > CD-ROM passthrough works with the cdrecord.
> >
> > Signed-off-by: Cong Meng <mc@xxxxxxxxxxxxxxxxxx>
> > ---
> > drivers/target/target_core_transport.c | 30 ++++++++++++++++++++++++++++++
> > include/scsi/scsi.h | 1 +
> > 2 files changed, 31 insertions(+), 0 deletions(-)
> >
> > diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
> > index 2d75c29..41439b3 100644
> > --- a/drivers/target/target_core_transport.c
> > +++ b/drivers/target/target_core_transport.c
> > @@ -2926,6 +2926,36 @@ static int transport_generic_cmd_sequencer(
> > size = (cdb[7] << 8) | cdb[8];
> > cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
> > break;
> > + case ATA_PASS_THROUGH_16:
> > + // T_LENGTH
> > + switch (cdb[2] & 0x3) {
> > + case 0x0:
> > + sectors = 0;
> > + break;
> > + case 0x1:
> > + sectors = (((cdb[1] & 0x1) ? cdb[3] : 0) << 8) | cdb[4];
> > + break;
> > + case 0x2:
> > + sectors = (((cdb[1] & 0x1) ? cdb[5] : 0) << 8) | cdb[6];
> > + break;
> > + case 0x3:
> > + pr_err("T_LENGTH=0x3 not supported\n");
> > + goto out_invalid_cdb_field;
> > + break;
> > + }
> > +
> > + // BYTE_BLOCK
> > + if (cdb[2] & 0x4) {
> > + // BLOCK
> > + // T_TYPE: 512 or sector
> > + size = sectors * ((cdb[2] & 0x10) ?
> > + dev->se_sub_dev->se_dev_attrib.block_size : 512);
> > + } else {
> > + // BYTE
> > + size = sectors;
> > + }
> > + cmd->se_cmd_flags |= SCF_SCSI_CONTROL_SG_IO_CDB;
>
> Mmmm, I think using SCF_SCSI_CONTROL_SG_IO_CDB here for all ATA
> passthrough cases should be OK with pSCSI, but you'll want to fail this
> type of cdb when if (!passthrough) for non pSCSI type devices to be safe
> with virtual backends..
(passthrough) has made sure the backend is non-virtual already.
As I doesn't set cmd->execute_task and SCF_SCSI_DATA_SG_IO_CDB flag, so
the below piece of code should guarantee that my patch only works with
pSCSI, at least, currently. Is it right?
---
passthrough =
(dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV);
...
if (!(passthrough || cmd->execute_task ||
(cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB)))
goto out_unsupported_cdb;
---
>
> Also just an FYI, checkpatch.pl will complain here using '//' style
> comments, so you'll want to always use '/* ... */' style comments when
> submitting a target patch.
Sure, I will change it.
Thanks.
mc
>
> So please go ahead and fix up these two bits + use ATA_16 following
> jejb's comment, and I'm fine with including your v2 into the for-3.5
> target queue..
>
> Thanks!
>
> --nab
>
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