Re: [PATCH 1/1] ahci: Do not receive interrupts sent by dummy ports
From: Tejun Heo
Date: Thu Apr 17 2014 - 13:06:58 EST
On Thu, Apr 17, 2014 at 06:06:15PM +0200, Alexander Gordeev wrote:
> In multiple MSI mode all AHCI ports (including dummy) get
> assigned separate MSI vectors and (as result of execution
> pci_enable_msi_exact() function) separate IRQ numbers,
> (mapped to the MSI vectors).
>
> Therefore, although interrupts from dummy ports are not
> desired they are still enabled. We do not request IRQs
> for dummy ports, but that only means we do not assign
> AHCI-specific ISRs to corresponding IRQ numbers.
>
> As result, dummy port interrupts still could come and
> traverse all the way from the PCI device to the kernel,
> causing unnecessary overhead.
>
> This update disables IRQs for dummy ports and prevents
> the described issue.
>
> Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: David Milburn <dmilburn@xxxxxxxxxx>
> Cc: linux-ide@xxxxxxxxxxxxxxx
David, can you please test the patch?
Thanks.
--
tejun
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/