Re: 2.6.24-rc2-mm1

[Gabriel C <nix.or.die@googlemail.com>]

Matthew Dharm wrote:
> On Wed, Nov 14, 2007 at 06:33:39AM +0100, Gabriel C wrote:
>> Matthew Dharm wrote:
>>> On Tue, Nov 13, 2007 at 07:49:24PM -0800, Greg KH wrote:
>>>> Matt, are these the errors you were worried about with the patch we were
>>>> just talking about tha tis in my tree?
>>> I can't tell from these logs.
>> There is the dmesg with CONFIG_USB_STORAGE_DEBUG :
>>
>> http://194.231.229.228/dmesg-2.6.24-rc2-mm1
> 
> Good news: This isn't the bug Greg was worried about.
> 
> Bad news: Something is seriously strange here.  Note the following from the
> logs:
> 
> Nov 14 06:07:43 lara [   41.890614] usb-storage: Bulk Status S 0x53425355 T 0xd R 0 Stat 0x0
> Nov 14 06:07:43 lara [   41.890616] usb-storage: -- unexpectedly short transfer
> 
> Note the 'R' value of zero -- this is the residue value.  It indicates a
> complete transfer, and that matches the log lines immediately previous
> which indicate a 4K transfer which completed properly.
> 
> If residue is zero, then srb->resid should be zero.  Take a look in
> linux/usb/storage/transport.c in usb_stor_Bulk_transport()
> 
> If srb->resid is zero, then you should NEVER get the "unexpectedly short
> transfer" message.  Look at usb_stor_invoke_transport() in the same file.

That code got replaced recently but I have no idea about it.

( http://git.kernel.org/?p=linux/kernel/git/jejb/scsi-misc-2.6.git;a=shortlog  see the patches from Boaz Harrosh) 

srb->resid got replaced by scsi_get_resid() it I see that right.

I'm CC'ing the author , he will know I think.

> 
> In fact, every transfer I look at shows this error.  I didn't exhaustivly
> check every single one in the log, but a quick scan suggests that they all
> are bogus; good transfer, CSW residue of 0, and "unexpectedly short"
> message.
> 
> Maybe I'm too tired at this hour, but I just don't see how this is
> possible.  Then again, I'm looking at 2.6.22 codebase (it's what I have
> handy).
> 
> Hrm... does this tree have the "srb accessor" patches in it?  I'm wondering
> if somewhere the init srb->resid to 0 before invoking the transport got
> lost....
> 
> Matt
> 


Gabriel