Re: Q: how to send ATA cmds to USB drive?

[Herbert Rosmanith <kernel@wildsau.enemy.org>]

>         int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
>         ...
>                 /*
>                  * If SCSI-2 or lower, store the LUN value in cmnd.
>                  */
>                 if (cmd->device->scsi_level <= SCSI_2) {
>                         cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
>                                        (cmd->device->lun << 5 & 0xe0);
>                 }
> 
> hm. now what .... ? If scsi-2 requires this, and the device is scsi-2.

actually, the scsi-level reported by the device is *not* 2.

it is set to 2 by "slave_configure" from drivers/usb/storage/scsiglue.c:

static int slave_configure(struct scsi_device *sdev)
{
...
        /* Set the SCSI level to at least 2.  We'll leave it at 3 if that's
         * what is originally reported.  We need this to avoid confusing
         * the SCSI layer with devices that report 0 or 1, but need 10-byte
         * commands (ala ATAPI devices behind certain bridges, or devices
                                              ^^^^^^^^^^^^^^^

the CY7C68310 is exactly that.

         * which simply have broken INQUIRY data).
...

        if (sdev->scsi_level < SCSI_2)
                sdev->scsi_level = sdev->sdev_target->scsi_level = SCSI_2;


kind regards,
h.rosmanith
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