Bug#604627: linux-image-2.6.32-5-amd64: megasas: Failed to alloc kernel SGL buffer for IOCTL

[Marc-Christian Petersen <m.c.p@gmx.de>]

so, what's up guys?

may we get this patch into Debian this year (2011)?

or should we wait for 21.12.2012? ;->

thanks!


Am 15.02.2011 um 8:32:48 Uhr schrieb Bjørn Mork <bjorn@mork.no>:

> Ben Hutchings <ben@decadent.org.uk> writes:
>> On Tue, 2011-01-25 at 09:24 +0100, Bjørn Mork wrote:
>>> Marc-Christian Petersen <m.c.p@gmx.de> writes:
>>>
>>>> so, what's up with this fix? Any chance to get it into Debians kernel tree?
>>>>
>>>> It's kind of uncomfortable to rebuild the whole kernel, with this applied,
>>>> when Debian releases a new kernel which happens frequently ;->
>>>
>>> I fully understand. I must admit that I thought it would be a no-brainer
>>> to verify this and get it into the upstream and the 2.6.32.x stable tree.  
>> [...]
>>
>> Your patch removes the initialisation of kern_sge32[i] when
>> ioc->sgl[i].iov_len is zero.  I think it should at least set the length
>> to zero.
> 
> Yes, you are of course right.  I just considered it's usage in that
> function, where it won't be used as long as kbuff_arr[i] is 0, but
> kern_sge32[i] should be set to be absolutely safe with the firmware.
> 
>> Perhaps it's safest to pass max(ioc->sgl[i].iov_len, 1) as the length
>> parameter to dma_alloc_coherent().
> 
> I agree that it would fix things, and that may be appropriate for a
> Debian specific workaround where the workaround context always is clear,
> but I don't think it's good as a permanent fix.  Reading the patched
> code would be very confusing.  Not allocating 0 is self-explanatory.
> 
> 
> Bjørn