Messages in this thread | | | Date | Mon, 7 Feb 2022 11:00:34 +0100 | Subject | Re: [PATCH 5/5] drm/stm: ltdc: add support of ycbcr pixel formats | From | yannick Fertre <> |
| |
Hi Nathan,
On 2/2/22 17:54, Nathan Chancellor wrote: > Hi Yannick, > > On Wed, Dec 15, 2021 at 10:48:43PM +0100, Yannick Fertre wrote: >> This patch adds the following YCbCr input pixel formats on the latest >> LTDC hardware version: >> >> 1 plane (co-planar) : YUYV, YVYU, UYVY, VYUY >> 2 planes (semi-planar): NV12, NV21 >> 3 planes (full-planar): YU12=I420=DRM YUV420, YV12=DRM YVU420 >> >> Signed-off-by: Yannick Fertre <yannick.fertre@foss.st.com> > > <snip> > >> +static inline void ltdc_set_ycbcr_config(struct drm_plane *plane, u32 drm_pix_fmt) >> +{ >> + struct ltdc_device *ldev = plane_to_ltdc(plane); >> + struct drm_plane_state *state = plane->state; >> + u32 lofs = plane->index * LAY_OFS; >> + u32 val; >> + >> + switch (drm_pix_fmt) { >> + case DRM_FORMAT_YUYV: >> + val = (YCM_I << 4) | LxPCR_YF | LxPCR_CBF; >> + break; >> + case DRM_FORMAT_YVYU: >> + val = (YCM_I << 4) | LxPCR_YF; >> + break; >> + case DRM_FORMAT_UYVY: >> + val = (YCM_I << 4) | LxPCR_CBF; >> + break; >> + case DRM_FORMAT_VYUY: >> + val = (YCM_I << 4); >> + break; >> + case DRM_FORMAT_NV12: >> + val = (YCM_SP << 4) | LxPCR_CBF; >> + break; >> + case DRM_FORMAT_NV21: >> + val = (YCM_SP << 4); >> + break; >> + case DRM_FORMAT_YUV420: >> + case DRM_FORMAT_YVU420: >> + val = (YCM_FP << 4); >> + break; >> + default: >> + /* RGB or not a YCbCr supported format */ >> + break; >> + } >> + >> + /* Enable limited range */ >> + if (state->color_range == DRM_COLOR_YCBCR_LIMITED_RANGE) >> + val |= LxPCR_YREN; >> + >> + /* enable ycbcr conversion */ >> + val |= LxPCR_YCEN; >> + >> + regmap_write(ldev->regmap, LTDC_L1PCR + lofs, val); >> +} > > This patch as commit 484e72d3146b ("drm/stm: ltdc: add support of ycbcr > pixel formats") in -next introduced the following clang warning: > > drivers/gpu/drm/stm/ltdc.c:625:2: warning: variable 'val' is used uninitialized whenever switch default is taken [-Wsometimes-uninitialized] > default: > ^~~~~~~ > drivers/gpu/drm/stm/ltdc.c:635:2: note: uninitialized use occurs here > val |= LxPCR_YCEN; > ^~~ > drivers/gpu/drm/stm/ltdc.c:600:9: note: initialize the variable 'val' to silence this warning > u32 val; > ^ > = 0 > 1 warning generated. > > Would it be okay to just return in the default case (maybe with a > message about an unsupported format?) or should there be another fix? > > Cheers,
Thanks for your help. It'okay for a message for unsupported format with a return in the default case. Do you want create & push the patch?
Best regards
| |