Re: [PATCH] SCSI, libata: add support for ATA_16 commands to libata ATAPI devices

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



James Bottomley wrote:
..
I don't think I quite understand what you're trying to do here.  My
understanding is that ATA_12 and ATA_16 are part of the SAT layer. i.e.
they're used when we're speaking SCSI to an underlying ATA device to
send taskfiles.  However, ATAPI devices don't use SAT ... every SCSI
command you send to an ATAPI device goes out as an ATA PACKET command
without being translated.

ATAPI devices also implement quite a few ATA (non-packet) commands.
This patch gives us a way to issue them in response to SG_IO ATA passthru
and the existing (non working) libata HDIO_DRIVE_CMD and HDIO_DRIVE_TASK
ioctl calls.

Without this patch, SCSI blocks the ATA_16 passthru attempts,
because it thinks the CDB is too large for the 12-byte packet protocol
that ATAPI devices use.  This limit (12 bytes) is totally non-applicable
to ATA protocol commands.

Is there a missing piece to this patch, where you scan the incoming
commands to ATAPI devices and actually do translation for ATA_16?

Look at the existing libata-core.c ioctl's for HDIO_DRIVE_CMD
and HDIO_DRIVE_TASK, used by hdparm and others.

Cheers
-
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Filesystems]     [Linux SCSI]     [Linux RAID]     [Git]     [Kernel Newbies]     [Linux Newbie]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Samba]     [Device Mapper]

  Powered by Linux