Re: [PATCH #upstream] ahci/sata_vsc: drop intx manipulation on msi enable

[Jeff Garzik <jeff@garzik.org>]

Tejun Heo wrote:
> There's no need to turn off intx explicitly on msi enable.  This is
> automatically handled by pci.  Drop it.
> 
> Note that, in sata_vsc's case, it was completely redundant; however,
> for ahci, it might be needed on machines if the BIOS turns intx off
> during boot.  However, there's no evidence of such behavior for ahci
> and the only such case seems to be ICH5 PATA according to ata_piix.
> Also, given the way ahci operates, it's highly unlikely BIOS ever
> disables IRQ for the controller.  However, as this change has slight
> possibility of introducing failure, please schedule it for #upstream.
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> ---
> There are similar places in sata_sis and sata_uli.  I have no idea
> whether they're there because they're needed or just copied over from
> other drivers.  Eh...

Most of them were just copied, IIRC.

as for this patch:  applied the ahci portion.

For sata_vsc, ISTR there being a hardware-specific reason why the 
MSI+INTX manipulation was done in that fashion.  Needs a bit of 
research, or at least, real world testing results for the MSI and !MSI 
cases...

	Jeff