On 2019-12-05 5:16 p.m., Liu, Zhan wrote: > > >> -----Original Message----- >> From: Alex Deucher <alexdeucher@xxxxxxxxx> >> Sent: 2019/December/05, Thursday 5:13 PM >> To: Liu, Zhan <Zhan.Liu@xxxxxxx> >> Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx; Deucher, Alexander >> <Alexander.Deucher@xxxxxxx> >> Subject: Re: [PATCH] drm/amdgpu/display: add fallthrough comment >> >> On Thu, Dec 5, 2019 at 5:10 PM Liu, Zhan <Zhan.Liu@xxxxxxx> wrote: >>> >>> >>> >>>> -----Original Message----- >>>> From: amd-gfx <amd-gfx-bounces@xxxxxxxxxxxxxxxxxxxxx> On Behalf Of >>>> Alex Deucher >>>> Sent: 2019/December/05, Thursday 4:39 PM >>>> To: amd-gfx@xxxxxxxxxxxxxxxxxxxxx >>>> Cc: Deucher, Alexander <Alexander.Deucher@xxxxxxx> >>>> Subject: [PATCH] drm/amdgpu/display: add fallthrough comment >>>> >>>> To avoid a compiler warning. >>>> >>>> Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> >>>> --- >>>> 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@xxxxxxx> > Interesting. It's described at [1] (search for -Wimplicit-fallthrough=3). Never knew that. This is also Reviewed-by: Harry Wentland <harry.wentland@xxxxxxx> [1] https://developers.redhat.com/blog/2017/03/10/wimplicit-fallthrough-in-gcc-7/ Harry >> >>> >>>> case >>>> AUX_TRANSACTION_REPLY_I2C_OVER_AUX_NACK: >>>> if (++aux_defer_retries >= >>>> AUX_MAX_DEFER_RETRIES) { >>>> goto fail; >>>> -- >>>> 2.23.0 >>>> >>>> _______________________________________________ >>>> amd-gfx mailing list >>>> amd-gfx@xxxxxxxxxxxxxxxxxxxxx >>>> >> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists. >>>> freedesktop.org%2Fmailman%2Flistinfo%2Famd- >>>> >> gfx&data=02%7C01%7Czhan.liu%40amd.com%7C77d85a0275aa4c0a78 >>>> >> 2f08d779cb9716%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C6 >>>> >> 37111788208702340&sdata=3m%2FuNuNIgq82z%2BAeXJ9y7wn81kV% >>>> 2FiDt3AyC3CDiTRrc%3D&reserved=0 > _______________________________________________ > amd-gfx mailing list > amd-gfx@xxxxxxxxxxxxxxxxxxxxx > https://lists.freedesktop.org/mailman/listinfo/amd-gfx > _______________________________________________ amd-gfx mailing list amd-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/amd-gfx
