[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH 7/7] ahci: work around bug with level interrupts
From: |
Alexander Graf |
Subject: |
Re: [Qemu-devel] [PATCH 7/7] ahci: work around bug with level interrupts |
Date: |
Tue, 1 Feb 2011 17:53:43 +0100 |
On 01.02.2011, at 17:34, Aurelien Jarno wrote:
> On Tue, Feb 01, 2011 at 03:51:32PM +0100, Alexander Graf wrote:
>> When using level based interrupts, the interrupt is treated the same as an
>> edge triggered one: leaving the line up does not retrigger the interrupt.
>>
>> In fact, when not lowering the line, we won't ever get a new interrupt inside
>> the guest. So let's always retrigger an interrupt as soon as the OS ack'ed
>> something on the device. This way we're sure the guest doesn't starve on
>> interrupts until someone fixes the actual interrupt path.
>
> Given this issue mostly concerns x86 and not other architectures where
> the SATA emulation can probably be used, what about putting the two
> versions of the codes like in i8259.c:
>
> | * all targets should do this rather than acking the IRQ in the cpu */
> | #if defined(TARGET_MIPS) || defined(TARGET_PPC) || defined(TARGET_ALPHA)
>
> The list of architectures here is reduced given the few architectures
> that actually use the i8259, so for ahci.c it should probably be #if not
> defined(TARGET_I386) instead.
Because then we'd have to build the ahci code conditionally on the
architecture. Right now it builds into libhw :)
Alex
[Qemu-devel] [PATCH 5/7] ahci: Implement HBA reset, Alexander Graf, 2011/02/01
[Qemu-devel] [PATCH 4/7] ahci: send init d2h fis on fis enable, Alexander Graf, 2011/02/01
[Qemu-devel] [PATCH 6/7] ahci: make number of ports runtime determined, Alexander Graf, 2011/02/01
[Qemu-devel] [PATCH 3/7] ahci: split ICH and AHCI even more, Alexander Graf, 2011/02/01
[Qemu-devel] [PATCH 1/7] ahci: split ICH9 from core, Alexander Graf, 2011/02/01
[Qemu-devel] [PATCH 2/7] ahci: add license header in ahci.h, Alexander Graf, 2011/02/01
[Qemu-devel] [PATCH 7/7] ahci: work around bug with level interrupts, Alexander Graf, 2011/02/01