Re: [PATCH v3 2/3] ui: Deliver refresh rate via QemuUIInfo

[Akihiko Odaki <akihiko.odaki@xxxxxxxxx>]

On 2022/06/09 21:02, Gerd Hoffmann wrote:
> On Thu, Jun 09, 2022 at 08:45:41PM +0900, Akihiko Odaki wrote:
> > On 2022/06/09 19:28, Gerd Hoffmann wrote:
> > > > --- a/include/ui/console.h
> > > > +++ b/include/ui/console.h
> > > > @@ -139,6 +139,7 @@ typedef struct QemuUIInfo {
> > > >        int       yoff;
> > > >        uint32_t  width;
> > > >        uint32_t  height;
> > > > +    uint32_t  refresh_rate;
> > > >    } QemuUIInfo;
> > > >    /* cursor data format is 32bit RGBA */
> > > > @@ -426,7 +427,6 @@ typedef struct GraphicHwOps {
> > > >        void (*gfx_update)(void *opaque);
> > > >        bool gfx_update_async; /* if true, calls graphic_hw_update_done() */
> > > >        void (*text_update)(void *opaque, console_ch_t *text);
> > > > -    void (*update_interval)(void *opaque, uint64_t interval);
> > > >        void (*ui_info)(void *opaque, uint32_t head, QemuUIInfo *info);
> > > >        void (*gl_block)(void *opaque, bool block);
> > > >    } GraphicHwOps;
> > > So you are dropping update_interval, which isn't mentioned in the commit
> > > message at all.  Also this patch is rather big.  I'd suggest:
> > >
> > > (1) add refresh_rate
> > > (2) update users one by one
> > > (3) finally drop update_interval when no user is left.
> > >
> > > thanks,
> > >     Gerd
> > I think 1 and 3 should have to be done once since refresh_rate and
> > update_interval would interfere with each other otherwise.
> Well, between 1 and 3 both old and new API are active.  Shouldn't be
> much of a problem because the GraphicHwOps implementations are using
> only the one or the other.
>
> take care,
>    Gerd
The only GraphicHwOps implementation updated with this change is xenfb. 
xenfb can be switched to use refresh_rate in step 1 or 3.
Switching to use refresh_rate in step 1 would break the refresh rate 
propagation until all host displays are updated to set refresh_rate 
instead of calling update_interval.
Switching to use refresh_rate in step 3 would break the refresh rate 
propagation when a host display is updated to set refresh_rate instead 
of calling update_interval but xenfb does not use refresh_rate.
Regards,
Akihiko Odaki