Re: Who's responsible for configuring CLS on a cardbus device?

From: Alan Cox
Date: Tue May 26 2009 - 09:23:06 EST

On Tue, 26 May 2009 22:05:08 +0900
Tejun Heo <tj@xxxxxxxxxx> wrote:

> Hello,
> This is regarding bko#13257.
> towerlexa@xxxxxx was experiencing very slow transfer rate when using a
> cardbus sata_sil SATA controller which is known to be sensitive to
> cache line size setting. The reset default is zero and no one
> configured it causing poor performance.
> This is solvable by simply setting CLS to the correct value but who's
> job is it? For non-hotplug devices, this is configured by the BIOS
> (at least on PC), so for hotplug devices I think falls on the lap of
> the PCI code but I'm not sure. If this is something which the
> sata_sil driver should be responsible for, is there an established way
> to determine the proper CLS value?

Currently its handled by pci_set_mwi() but there isn't actually a more
direct way to do this.

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