Re: [Qemu-devel] [PATCH] ati-vga: i2c fix

[BALATON Zoltan]

On Fri, 15 Mar 2019, Gerd Hoffmann wrote:
> On Thu, Mar 14, 2019 at 08:11:21PM +0100, BALATON Zoltan wrote:
> > On Thu, 14 Mar 2019, Gerd Hoffmann wrote:
> > > gets radeonfb going for me, on top of your i2c patches.
> > > ---
> > > @@ -512,15 +531,15 @@ static void ati_mm_write(void *opaque, hwaddr addr,
> > >         if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
> > >             break;
> > >         }
> > > -        s->regs.gpio_vga_ddc = data & 0xf000f;
> > > -        if (data & BIT(17)) {
> > > -            s->regs.gpio_monid |= !!(data & BIT(1)) << 9;
> > > -            bitbang_i2c_set(s->bbi2c, BITBANG_I2C_SCL, (data & BIT(1)) != 0);
> > > -        }
> > > -        if (data & BIT(16)) {
> > > -            s->regs.gpio_monid |= bitbang_i2c_set(s->bbi2c, BITBANG_I2C_SDA,
> > > -                                                  data & BIT(0)) << 8;
> > > +#if 0
> > > +        s->regs.gpio_vga_ddc = ati_i2c(s->bbi2c, data);
> > > +#endif
> >
> > Thanks, I'll try and merge this. What's this #if 0 line?
>
> Avoid the monitor show up on both vga ...
>
> > Regards,
> > BALATON Zoltan
> >
> > > +        break;
> > > +    case GPIO_DVI_DDC:
> > > +        if (s->dev_id == PCI_DEVICE_ID_ATI_RAGE128_PF) {
> > > +            break;
> > >         }
> > > +        s->regs.gpio_dvi_ddc = ati_i2c(s->bbi2c, data);
>
> ... and dvi.
>
> A more correct model would probably be to create two i2c busses for
> that, then hook up the ddc to one of them (possibly depending on a
> config option).

Isn't it enough to only emulate the DVI port DDC then? I've sent an 
updated patch as v2 that also cleans up the bitbang_i2c.h header 
inclusion. (I've checked that Linux first checks DVI then VGA so my 
original patch may have also worked if the copy paste error is fixed and 
updated the right reg bits instead of gpio_monid. But let's go with the 
default and use a DVI port, then we likely not need VGA as we don't have 
a mointor there.)

Regards,
BALATON Zoltan