[PATCH] drm/amdgpu/display: add fallthrough comment

[Liu, Zhan]

> -----Original Message-----
> From: Alex Deucher <alexdeucher at gmail.com>
> Sent: 2019/December/05, Thursday 5:13 PM
> To: Liu, Zhan <Zhan.Liu at amd.com>
> Cc: amd-gfx at lists.freedesktop.org; Deucher, Alexander
> <Alexander.Deucher at amd.com>
> Subject: Re: [PATCH] drm/amdgpu/display: add fallthrough comment
> 
> On Thu, Dec 5, 2019 at 5:10 PM Liu, Zhan <Zhan.Liu at amd.com> wrote:
> >
> >
> >
> > > -----Original Message-----
> > > From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
> > > Alex Deucher
> > > Sent: 2019/December/05, Thursday 4:39 PM
> > > To: amd-gfx at lists.freedesktop.org
> > > Cc: Deucher, Alexander <Alexander.Deucher at amd.com>
> > > Subject: [PATCH] drm/amdgpu/display: add fallthrough comment
> > >
> > > To avoid a compiler warning.
> > >
> > > Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> > > ---
> > >  drivers/gpu/drm/amd/display/dc/dce/dce_aux.c | 1 +
> > >  1 file changed, 1 insertion(+)
> > >
> > > diff --git a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
> > > b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
> > > index 191b68b8163a..f1a5d2c6aa37 100644
> > > --- a/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
> > > +++ b/drivers/gpu/drm/amd/display/dc/dce/dce_aux.c
> > > @@ -645,6 +645,7 @@ bool dce_aux_transfer_with_retries(struct
> > > ddc_service *ddc,
> > >                       case AUX_TRANSACTION_REPLY_AUX_DEFER:
> > >                       case
> > > AUX_TRANSACTION_REPLY_I2C_OVER_AUX_DEFER:
> > >                               retry_on_defer = true;
> > > +                             /* fall through */
> >
> > I am a bit confusing here. Why a comment can avoid a compiler warning?
> 
> The kernel enables fall through warnings, so unless there is a comment
> mentioning that are are expecting to fall through here, we get a warning.
> The idea is to find missing breaks in switch code.
> 
> Alex

Got you. Thank you for your explanation.

Reviewed-by: Zhan Liu <zhan.liu at amd.com>

> 
> >
> > >                       case
> > > AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK:
> > >                               if (++aux_defer_retries >=
> > > AUX_MAX_DEFER_RETRIES) {
> > >                                       goto fail;
> > > --
> > > 2.23.0
> > >
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