Re: Clean patch to fix not working spindown over Firewire

[Stefan Richter <stefanr@s5r6.in-berlin.de>]

> 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 ; 
>>  

PS:
The power conditions should be supported by many more devices besides
RBC devices.  Only SAT (and hence libata) and Linux' "File-backed USB
Storage Gadget" (drivers/usb/gadget/file_storage.c) have objections
against power condition.

But it's less intrusive if we enable it only for RBC for now because we
now have a good idea about how well it is supported by them.
-- 
Stefan Richter
-=====-==--- -=-= -=--=
http://arcgraph.de/sr/