From: Tejun Heo <tj@kernel.org>
To: Alexander Gordeev <agordeev@redhat.com>
Cc: linux-kernel@vger.kernel.org, David Milburn <dmilburn@redhat.com>,
linux-ide@vger.kernel.org
Subject: Re: [PATCH 1/1] ahci: Do not receive interrupts sent by dummy ports
Date: Fri, 18 Apr 2014 15:56:50 -0400 [thread overview]
Message-ID: <20140418195650.GJ23576@htj.dyndns.org> (raw)
In-Reply-To: <dbaed51ffe73dec1966eba256c3b42ed22ed58f3.1397750166.git.agordeev@redhat.com>
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@redhat.com>
> Cc: Tejun Heo <tj@kernel.org>
> Cc: David Milburn <dmilburn@redhat.com>
> Cc: linux-ide@vger.kernel.org
Applied to libata/for-3.15-fixes w/ David's tested-by added.
Thanks.
--
tejun
prev parent reply other threads:[~2014-04-18 19:56 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-17 16:06 [PATCH 0/1] ahci: Do not receive interrupts sent by dummy ports Alexander Gordeev
2014-04-17 16:06 ` [PATCH 1/1] " Alexander Gordeev
2014-04-17 17:06 ` Tejun Heo
2014-04-17 17:50 ` David Milburn
2014-04-18 19:56 ` Tejun Heo [this message]
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