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SubjectRe: [PATCH v4 -tip 3/3] AHCI: Support multiple MSIs
On 11/19/2012 10:02 AM, Alexander Gordeev wrote:
> Take advantage of multiple MSIs implementation on x86 - on systems with
> IRQ remapping AHCI ports not only get assigned separate MSI vectors -
> but also separate IRQs. As result, interrupts generated by different
> ports could be serviced on different CPUs rather than on a single one.
>
> In cases when number of allocated MSIs is less than requested the Sharing
> Last MSI mode does not get used, no matter implemented in hardware or not.
> Instead, the driver assumes the advantage of multiple MSIs is negated and
> falls back to the single MSI mode as if MRSM bit was set (some Intel chips
> implement this strategy anyway - MRSM bit gets set even if the number of
> allocated MSIs exceeds the number of implemented ports).
>
> Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
> ---
> drivers/ata/ahci.c | 93 +++++++++++++++++++++++++++++++++++++--
> drivers/ata/ahci.h | 6 +++
> drivers/ata/libahci.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++---
> 3 files changed, 207 insertions(+), 10 deletions(-)

Acked-by: Jeff Garzik <jgarzik@redhat.com>





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