Re: Clean patch to fix not working spindown over Firewire

Stefan Richter
2008-05-09T21:13:54Z

On 9 May, Tino Keitel wrote:
> On Wed, Apr 30, 2008 at 15:36:36 +0200, Stefan Richter wrote:
>> If it works for all RBC devices (it should according to the spec...) &&
>> your ICY Box exposes itself as RBC device (it should do so), then we
>> don't need any changes to struct scsi_device and to sbp2/ firewire-sbp2.
>
> Do you mean something like in the attached (untested) patch?
>
> Regards,
> Tino
>
> diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
> index 01cefbb..6b927f6 100644
> --- a/drivers/scsi/sd.c
> +++ b/drivers/scsi/sd.c
> @@ -1787,8 +1787,13 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
> struct scsi_device *sdp = sdkp->device;
> int res;
>
> - if (start)
> + if (start) {
> cmd[4] |= 1; /* START */
> + /* active power condition */
> + cmd[4] |= (sdp->type == TYPE_RBC) ? (1 << 4) : 0;
> + } else
> + /* standby power condition */
> + cmd[4] |= (sdp->type == TYPE_RBC) ? (3 << 4) : 0 ;
>
> if (!scsi_device_online(sdp))
> return -ENODEV;

Yes, that's what I meant. Would you test it on your disks and, if it
works, repost to LSML with your Signed-off-by line?
(See linux/Documentation/SubmittingPatches.)

Or write it as

if (start)
cmd[4] |= 1; /* START */
+
+ if (sdp->type == TYPE_RBC)
+ cmd[4] |= start ? 1 << 4 : 3 << 4; /* POWER CONDITION */

Alas the test for TYPE_RBC is not ideal. As I wrote in my other mail,
there are some SBP-2 disks which pose as TYPE_DISK. It's not a big
problem though because almost all of them also work with POWER
CONDITION = 0. The only exception is DViCO Momobay CX-1 which goes
belly-up POWER CONDITION = 0 and START = 0. Maybe I should simply
overwrite the CX-1's sdp->type by TYPE_RBC. I suspect that this is what
it implements anyway. The firmwares of the later Momobay models FX-3A
and IIRC CX-2 do so.
--
Stefan Richter
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