Re: [Qemu-devel] [PATCH 10/24] ide: add trigger_irq callback

[Paolo Bonzini <pbonzini@redhat.com>]

Il 30/10/2013 14:34, Kevin Wolf ha scritto:
>> > 
>> > The problem is that the IRQ ack is done differently in AHCI (using the
>> > write-1-clears register PORT_IRQ_STAT; PORT_IRQ_MASK can also modify the
>> > status of the interrupt line) and PATA (reading 0x1f7).
> I don't understand how this is related; I'm really talking about
> internal interfaces here. ide_set_irq() and .trigger_irq() are really
> two different ways for the IDE core to communicate that an IRQ should be
> triggered. They can in theory be used for the same things, but are used
> inconsistently.

Looking at the history of BM_STATUS_INT, I found this commit of yours:

    ide/core: Remove explicit setting of BM_STATUS_INT
    
    BM_STATUS_INT is automatically set during ide_set_irq(), there's no reason to
    set it manually in addition.
    
    There is even one case where the interrupt status bit was set, but no IRQ was
    raised. This is when the PRD table was reached but there is more data to
    transfer. The correct behaviour for this case is not to set BM_STATUS_INT.
    
    Signed-off-by: Kevin Wolf <kwolf@redhat.com>

(commit 69c38b8fcec823da05f98f6ea98ec2b0013d64e2).

It seems to me that the remaining use of BM_STATUS_INT, which this
patch changes to trigger_irq, is also due to a short PRD.  So the trigger_irq
callback can go away altogether.

Paolo