Re: [PATCH 3/3 pci#linux-next] pccard: configure CLS on attach

From: Tejun Heo
Date: Tue Sep 22 2009 - 21:20:27 EST


Hello, Axel.

Axel Birndt wrote:
> Tejun Heo schrieb:
>> For non hotplug PCI devices, the system firmware usually configures
>> CLS correctly. For pccard devices system firmware can't do it and
>> Linux PCI layer doesn't do it either. Unfortunately this leads to
>> poor performance for certain devices (sata_sil). Unless MWI, which
>> requires separate configuration, is to be used, CLS doesn't affect
>> correctness, so the configuration should be harmless.
>>
>> This patch makes pci_set_cacheline_size() always built and export it
>> and make pccard call it during attach.
>>
>> Please note that some other PCI hotplug drivers (shpchp and pciehp)
>> also configure CLS on hotplug.
>
> i would like to ask, when this patch is usable for normal guy's, like me.
> could you tell me in which kernel release or in which bugfix this will
> be implemented?
>
> currently i'am using Kubuntu 8.04 with all current released bugfixes and
> kernel updates...

This patch is rather dangerous and should sit out for a while in
linux-next and then -rc. In mainline, I think it will appear in
2.6.33. Distros may choose to backport them but I don't think they'll
do it before the change at least lands on -rc which is at least 3+
months away. It's also possible for distros to backport it but enable
it only if certain kernel parameter is set but you'll have to ask each
distro whether they're willing to do such thing.

Thanks.

--
tejun
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