Re: [PATCH] scsi: vpd pages are mandatory for SPC-2

[Hannes Reinecke <hare@suse.de>]

On 03/16/2016 08:38 AM, Hannes Reinecke wrote:
> On 03/15/2016 10:36 PM, Martin K. Petersen wrote:
>>>>>>> "Hannes" == Hannes Reinecke <hare@suse.de> writes:
>>
>>>> I wonder how many non-compliant devices we would have to blacklist as
>>>> a result of this change...
>>
>> Hannes> But it feels even sillier having to whitelist every
>> Hannes> standards-conformant device here; I certainly was when I figured
>> Hannes> that EMC Clariion won't work properly without this patch.
>>
>> Hannes> And the idea was to mark off _misbehaving_ drives, not the other
>> Hannes> way round.
>>
>> I understand. But my concern is that the number of broken USB doodad
>> model strings far outnumber enterprise storage vendor ditto. And there
>> is no point in reversing the polarity if it increases the maintenance
>> burden.
>>
>> So I would be more comfortable with just widening the VPD whitelist and
>> assume that everything with an EMC, Dell, NetApp, whatever vendor ID is
>> compliant.
>>
> Well, yes, that's the bugger. You never know until you try.
> 
> But we have been asking for VPD pages per default for quite some
> time now from userspace (thanks to udev), and so far have had only a
> few bug reports for misbehaving devices.
> 
> And again, it just feels wrong to punish every well-behaved device
> out there, for the sake of some buggy USB implementation of a few
> bucks worth.
> 
And incidentally, for most USB drives VPD pages are already blanked out:

drivers/usb/storage/scsiglue.c:slave_configure()
[ .. ]
		/* Some devices don't handle VPD pages correctly */
		sdev->skip_vpd_pages = 1;


So it looks we're dealing with a non-issue here.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		   Teamlead Storage & Networking
hare@suse.de			               +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
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