Re: [PATCH] drm/msm/dp: fix error check return value of irq_of_parse_and_map()

[Dmitry Baryshkov]

On 22/04/2022 21:39, Stephen Boyd wrote:
> Quoting cgel.zte@xxxxxxxxx (2022-04-22 01:49:51)
> > From: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
> >
> > The irq_of_parse_and_map() function returns 0 on failure, and does not
> > return an negative value.
> >
> > Fixes:  8ede2ecc3e5e ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
> > Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
> > Signed-off-by: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/msm/dp/dp_display.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> > index a42732b67349..3926d2ac107d 100644
> > --- a/drivers/gpu/drm/msm/dp/dp_display.c
> > +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> > @@ -1239,7 +1239,7 @@ int dp_display_request_irq(struct msm_dp *dp_display)
> >          dp = container_of(dp_display, struct dp_display_private, dp_display);
> >
> >          dp->irq = irq_of_parse_and_map(dp->pdev->dev.of_node, 0);
>
> Why can't platform_get_irq() be used?
>
> > -       if (dp->irq < 0) {
> > +       if (!dp->irq) {
> >                  rc = dp->irq;
>
> zero as an error return value is an error?

Hmm, nice catch. Please fix it. And the other patch too.

> >                  DRM_ERROR("failed to get irq: %d\n", rc);
> >                  return rc;


--
With best wishes
Dmitry