[SeaBIOS] [PATCH 0/7] vgabios improvements

[Kevin O'Connor]

On Wed, Apr 16, 2014 at 06:17:45PM +0200, Gerd Hoffmann wrote:
>   Hi,
> 
> > --- a/src/hw/ata.c
> > +++ b/src/hw/ata.c
> 
> > -            pci_config_maskw(bdf, PCI_COMMAND, 0, PCI_COMMAND_MASTER);
> > +            pci_config_maskw(bdf, PCI_COMMAND, 0, PCI_COMMAND_MASTER | PCI_COMMAND_IO | PCI_COMMAND_MEMORY);
> 
> Ah.  I think that should go in.  If we need it, we better make sure it
> is enabled instead of expecting someone else to do it.  It's more
> robust, even if it should not be needed in theory.
> 
> That patch also makes CONFIG_ATA_DMA=y on CONFIG_QEMU=y builds work.

On CONFIG_QEMU=y, pciinit.c turns those bits on, so it isn't needed in
ata.c.  On real hardware coreboot used to enable those bits, as I used
to use CONFIG_ATA_DMA=y on my boards.  (Recently, all my boards have
AHCI, so I use that instead and I'm not sure I can retest on real
hardware.)

In any case, I guess there is no harm in doing the above.  It's just
odd that coreboot doesn't turn it on.  That said, CONFIG_ATA_DMA is
very fragile and it may be worth just removing at some point.

-Kevin