Re: [PATCH 18/24] display/sm501 display/ati: Fix to realize "i2c-ddc"

[Philippe Mathieu-Daudé]

On 5/18/20 12:39 PM, BALATON Zoltan wrote:
> On Mon, 18 May 2020, Markus Armbruster wrote:
> > sm501_init() and ati_vga_realize() create an "i2c-ddc" device, but
> > neglect to realize it.  Affects machines sam460ex, shix, r2d, and
> > fulong2e.
> >
> > I wonder how this ever worked.  If the "device becomes real only on
> > realize" thing actually works, then we've always been missing the
> > device, yet nobody noticed.
> >
> > Fix by realizing it right away.  Visible in "info qom-tree"; here's
> > the change for sam460ex:
> >
> >     /machine (sam460ex-machine)
> >       [...]
> >       /unattached (container)
> >         [...]
> >    -    /device[14] (sii3112)
> >    +    /device[14] (i2c-ddc)
> >    +    /device[15] (sii3112)
> >         [rest of device[*] renumbered...]
> >
> > Fixes: 4a1f253adb45ac6019971193d5077c4d5d55886a
> > Fixes: 4a1f253adb45ac6019971193d5077c4d5d55886a
>
> One of these is probably meant to be 
> c82c7336de58876862e6b4dccbda29e9240fd388

:)

> although I'm not sure having a Fixes tag makes sense for this commit.

AFAIK the 'Fixes' tag is not well defined in QEMU.
I personally find it handy to navigate between commits in gitk, not 
having to go via unrelated commits, which is why I use it.
Linux kernel seems to have a stricter approach, only using it for 
security bug fixes. For this QEMU uses 'Cc: qemu-stable'.

Do we need to clarify its use on the wiki?

> > Cc: BALATON Zoltan <address@hidden>
> > Cc: address@hidden
> > Cc: Magnus Damm <address@hidden>
> > Cc: Philippe Mathieu-Daudé <address@hidden>
> > Cc: Aleksandar Markovic <address@hidden>
> > Signed-off-by: Markus Armbruster <address@hidden>
> > ---
> > hw/display/ati.c   | 1 +
> > hw/display/sm501.c | 1 +
> > 2 files changed, 2 insertions(+)
> >
> > diff --git a/hw/display/ati.c b/hw/display/ati.c
> > index 58ec8291d4..7c2177d7b3 100644
> > --- a/hw/display/ati.c
> > +++ b/hw/display/ati.c
> > @@ -929,6 +929,7 @@ static void ati_vga_realize(PCIDevice *dev, Error 
> > **errp)
> >     bitbang_i2c_init(&s->bbi2c, i2cbus);
> >     I2CSlave *i2cddc = I2C_SLAVE(qdev_create(BUS(i2cbus), TYPE_I2CDDC));
> >     i2c_set_slave_address(i2cddc, 0x50);
> > +    qdev_init_nofail(DEVICE(i2cddc));
> >
> >     /* mmio register space */
> >     memory_region_init_io(&s->mm, OBJECT(s), &ati_mm_ops, s,
> > diff --git a/hw/display/sm501.c b/hw/display/sm501.c
> > index acc692531a..132e75b641 100644
> > --- a/hw/display/sm501.c
> > +++ b/hw/display/sm501.c
> > @@ -1816,6 +1816,7 @@ static void sm501_init(SM501State *s, 
> > DeviceState *dev,
> >     /* ddc */
> >     I2CDDCState *ddc = I2CDDC(qdev_create(BUS(s->i2c_bus), TYPE_I2CDDC));
> >     i2c_set_slave_address(I2C_SLAVE(ddc), 0x50);
> > +    qdev_init_nofail(DEVICE(ddc));
> >
> >     /* mmio */
> >     memory_region_init(&s->mmio_region, OBJECT(dev), "sm501.mmio", 
> > MMIO_SIZE);