Re: [PATCH] drm/bridge: adv7511: Exit interrupt handling when necessary

[Sui Jingfeng]

Hi,

On 5/20/24 06:11, Dmitry Baryshkov wrote:
> On Thu, May 16, 2024 at 06:10:06PM +0800, Liu Ying wrote:
> > Commit f3d9683346d6 ("drm/bridge: adv7511: Allow IRQ to share GPIO pins")
> > fails to consider the case where adv7511->i2c_main->irq is zero, i.e.,
> > no interrupt requested at all.
> >
> > Without interrupt, adv7511_wait_for_edid() could return -EIO sometimes,
> > because it polls adv7511->edid_read flag by calling adv7511_irq_process()
> > a few times, but adv7511_irq_process() happens to refuse to handle
> > interrupt by returning -ENODATA.  Hence, EDID retrieval fails randomly.
> >
> > Fix the issue by checking adv7511->i2c_main->irq before exiting interrupt
> > handling from adv7511_irq_process().
> >
> > Fixes: f3d9683346d6 ("drm/bridge: adv7511: Allow IRQ to share GPIO pins")
> > Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
> > ---
> >   drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 3 ++-
> >   1 file changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > index 6089b0bb9321..2074fa3c1b7b 100644
> > --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> > @@ -479,7 +479,8 @@ static int adv7511_irq_process(struct adv7511 *adv7511, bool process_hpd)
> >   		return ret;
> >   
> >   	/* If there is no IRQ to handle, exit indicating no IRQ data */
> > -	if (!(irq0 & (ADV7511_INT0_HPD | ADV7511_INT0_EDID_READY)) &&
> > +	if (adv7511->i2c_main->irq &&
> > +	    !(irq0 & (ADV7511_INT0_HPD | ADV7511_INT0_EDID_READY)) &&
> >   	    !(irq1 & ADV7511_INT1_DDC_ERROR))
> >   		return -ENODATA;
>
> I think it might be better to handle -ENODATA in adv7511_wait_for_edid()
> instead. WDYT?

I think this is may deserve another patch.

--
Best regards
Sui