Re: [Qemu-devel] [PULL] Standard SD host controller model

[Peter Maydell]

On 29 June 2012 15:52, Igor Mitsyanko <address@hidden> wrote:
> On 06/29/2012 02:59 PM, Peter Maydell wrote:
>> The irq code looks dubious: we seem to have a single output
>> irq, but the code does things like:
>>     qemu_set_irq(sdhci->irq, sdhci->errintsigen & sdhci->errintsts);
>> but in other code paths:
>>     qemu_set_irq(sdhci->irq, sdhci->norintsigen & sdhci->norintsts);
>> It seems much more likely that the hardware has various interrupt
>> conditions which are effectively ORed together than that there
>> are some cases where the interrupt line is driven by one condition
>> and some where it's driven by the other.
>
> Sure, full interrupt trigger condition would be
> if ((s->norintsts & s->norintsigen) || (s->errintsts & s->errintsigen) ||
>        ((s->norintsts & SDHC_NIS_INSERT) && (s->wakcon & SDHC_WKUP_ON_INS))
> ||
>        ((s->norintsts & SDHC_NIS_REMOVE) && (s->wakcon & SDHC_WKUP_ON_RMV)))
>
> but there's no point in using full check everywhere, if execution of some
> specific code block could result in generation of normal interrupt request
> only (bits in norintsts) or error interrupt request only (bits in
> errintsts), then its the only condition we need to check.

But what if there was already a norintsts interrupt asserted, and this
code path is for the errintsts? Then if the errintsigen is such that
the errintsts is masked, you've just set the irq line to 0 and dropped
the norintsts interrupt, haven't you?

-- PMM