Sebastian Kemper reported that issuing CD/DVD commands under libata
is not fully compatible with ide-scsi. In particular, the GPCMD_SET_STREAMING
was being rejected at the host level in some instances.
The reason is that libata-scsi insists upon the cmd_len field exactly matching
the SCSI opcode being issued, whereas ide-scsi tolerates 12-byte commands
contained within a 16-byte (cmd_len) CDB.
There doesn't seem to be a good reason for us to not be compatible there,
so here is a patch to fix libata-scsi to permit SCSI opcodes so long as
they fit within whatever size CDB is provided.
Signed-off-by: Mark Lord <mlord@pobox.com>
---
Patch is against 2.6.24-rc2-git4.
Sebastian, could you please re-test with this patch
and let us know that it works for you (or not).
--- old/drivers/ata/libata-scsi.c 2007-11-13 23:25:15.000000000 -0500
+++ linux/drivers/ata/libata-scsi.c 2007-11-14 12:32:16.000000000 -0500
@@ -2869,7 +2869,8 @@
xlat_func = NULL;
if (likely((scsi_op != ATA_16) || !atapi_passthru16)) {
/* relay SCSI command to ATAPI device */
- if (unlikely(scmd->cmd_len > dev->cdb_len))
+ int len = COMMAND_SIZE(scsi_op);
+ if (unlikely(len > scmd->cmd_len || len > dev->cdb_len))
goto bad_cdb_len;
xlat_func = atapi_xlat;
-
