Re: [Qemu-devel] [PATCH 1/3] ide: don't loose pending dma state

[Pavel Butsykin]

On 24.03.2016 17:07, Paolo Bonzini wrote:
> On 24/03/2016 14:38, Pavel Butsykin wrote:
> > Look at the ide_sector_read_cb function. The ->dma_cmd field is used
> > only for the DMA, we can't use the ide_cmd_is_read macro for PIO or
> > ATAPI. In fact, the ide_handle_rw_error looks like a generic function
> > and I do not see any good reason to move the handling of the dma_cmd
> > field(especially in the context of bug fixes).
>
> I agree now.
>
> > > However, if it works, using dma_cmd would be better than using the
> > > dma_cb.
> > We can't use the dma_cmd field to build the ATAPI ->error_status. Your
> > proposal is quite logical, but please look at the 3rd patch, there to
> > build ->error_status we can use the same dma_cb, it is very convenient.
>
> Couldn't you just add a new dma_cmd value IDE_DMA_ATAPI, and set it
> before every call to ide_start_dma(s, ide_atapi_cmd_read_dma_cb)?
You want something like this:
dma_cb()
{
...
    if (ret < 0) {
        if (ide_handle_rw_error(s, -ret, ide_dma_cmd_to_retry(s))) {
            return;
        }
    }
...
}

static void ide_bmdma_pre_save(void *opaque)
{
...
    if (!(bm->status & BM_STATUS_DMAING) && bm->dma_cb) {
        bm->bus->error_status = ide_dma_cmd_to_retry(bmdma_active_if(bm));
    }
...
}

??

> Thanks,
>
> Paolo