On 04/17/2014 12:06 PM, Tejun Heo wrote:
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?
Hi,
I have re-tested successfully, this patch prevents the crash
when using kdump, and I boot tested a system that boots off
ahci and has dummy ports present, no problems seen.
Thanks,
David
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