Re: [PATCH qemu 1/2] hw/at24c : modify at24c to support 1 byte address mode

[Peter Delevoryas]

On Tue, Feb 14, 2023 at 03:29:33PM +0100, Cédric Le Goater wrote:
> On 2/10/23 07:20, ~ssinprem wrote:
> > From: Sittisak Sinprem <ssinprem@celestca.com>
> 
> 
> 
> You will need to add a Signed-off-by tag
> 
> Thanks,
> 
> C.

Oh, yeah this is a pretty good change: I mean, at first I had no idea what's
going on here, so it would be nice if we could leave a comment or refactor it
to be simpler.

Maybe instead of if-statements for > 256 or <= 256, we could do an address size
attribute and compute the 256 bound from the address size.

Anyways, this is a really small change to fix behavior, we can do a refactoring
like that later (If Cedric is ok with it).

Reviewed-by: Peter Delevoryas <peter@pjd.dev>

> 
> > ---
> >   hw/nvram/eeprom_at24c.c | 8 +++++---
> >   1 file changed, 5 insertions(+), 3 deletions(-)
> > 
> > diff --git a/hw/nvram/eeprom_at24c.c b/hw/nvram/eeprom_at24c.c
> > index 2d4d8b952f..693212b661 100644
> > --- a/hw/nvram/eeprom_at24c.c
> > +++ b/hw/nvram/eeprom_at24c.c
> > @@ -87,7 +87,7 @@ uint8_t at24c_eeprom_recv(I2CSlave *s)
> >       EEPROMState *ee = AT24C_EE(s);
> >       uint8_t ret;
> > -    if (ee->haveaddr == 1) {
> > +    if (ee->rsize > 256 && ee->haveaddr == 1) {
> >           return 0xff;
> >       }
> > @@ -104,11 +104,13 @@ int at24c_eeprom_send(I2CSlave *s, uint8_t data)
> >   {
> >       EEPROMState *ee = AT24C_EE(s);
> > -    if (ee->haveaddr < 2) {
> > +    if ((ee->rsize > 256 && ee->haveaddr < 2) ||
> > +        (ee->rsize <= 256 && ee->haveaddr < 1)) {
> >           ee->cur <<= 8;
> >           ee->cur |= data;
> >           ee->haveaddr++;
> > -        if (ee->haveaddr == 2) {
> > +        if ((ee->rsize > 256 && ee->haveaddr == 2) ||
> > +            (ee->rsize <= 256 && ee->haveaddr == 1)) {
> >               ee->cur %= ee->rsize;
> >               DPRINTK("Set pointer %04x\n", ee->cur);
> >           }
>