Re: [PATCH RESEND 1/2] SCSI: use scsi_device->timeout consistently

[Tejun Heo <htejun@gmail.com>]

Kai Makisara wrote:
> On Sun, 19 Nov 2006, Tejun Heo wrote:
> 
>> Each high level driver uses scsi_device->timeout diffrently.
>>
> ...
>> Index: scsi-misc-2.6/drivers/scsi/st.c
>> ===================================================================
>> --- scsi-misc-2.6.orig/drivers/scsi/st.c
>> +++ scsi-misc-2.6/drivers/scsi/st.c
>> @@ -3986,7 +3986,8 @@ static int st_probe(struct device *dev)
>>  	tpnt->partition = 0;
>>  	tpnt->new_partition = 0;
>>  	tpnt->nbr_partitions = 0;
>> -	tpnt->device->timeout = ST_TIMEOUT;
>> +	if (!SDp->timeout)
>> +		SDp->timeout = ST_TIMEOUT;
> 
> I don't think this should be done. It probably makes the default timeout 
> way too short. The error recovery with tapes takes a long time. The user 
> can change the timeout if the default (900 seconds) seems too long (or 
> short).
> 
> I don't think there is anything in the midlevel or low-level code to set 
> the timeout based on the device characteristics. This is left to the ULD.

Low level driver should configure timeout or retries to a known value 
iff it knows what it's doing, when it knows both transport and 
device-type specific characteristic.  AFAICS, the only driver which 
modifies sdev->timeout is ipr and it does so only when it knows the 
device is of certain type.  So, I don't think it will cause any trouble, 
and using different initialization in different ULDs is too subtle.

Thanks.

-- 
tejun