| Message ID | 20240628-gcc5-v1-1-7cd56f04a6a8@chromium.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: imx-pxp: Rewrite coeff expression | expand |
On Fr, 2024-06-28 at 15:11 +0000, Ricardo Ribalda wrote: > GCC5 cannot figure out that the expressions are constant, and that > triggers a build failure. Rewrite the expressions. > > The following gcc5 error is workaround: > > #define BM_PXP_CSC1_COEF0_YCBCR_MODE 0x80000000 > ^ > BM_PXP_CSC1_COEF0_YCBCR_MODE | > ^ > #define BM_PXP_CSC1_COEF0_YCBCR_MODE 0x80000000 > ^ > > drivers/media/platform/nxp/imx-pxp.c: In function 'pxp_setup_csc': > drivers/media/platform/nxp/imx-pxp.h:582:38: error: initializer element is not constant > drivers/media/platform/nxp/imx-pxp.c:374:4: note: in expansion of macro 'BM_PXP_CSC1_COEF0_YCBCR_MODE' > drivers/media/platform/nxp/imx-pxp.h:582:38: note: (near initialization for 'csc1_coef_bt601_lim[0]') > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> Can you elaborate on how this is triggered? At least I couldn't reproduce this by just copy & pasting the csc1_coef_bt601_lim initializer and the required macros into gcc 5.4 on godbolt. Can this be fixed by using GENMASK / FIELD_PREP instead? regards Philipp
Hi Philipp On Mon, 1 Jul 2024 at 11:30, Philipp Zabel <p.zabel@pengutronix.de> wrote: > > On Fr, 2024-06-28 at 15:11 +0000, Ricardo Ribalda wrote: > > GCC5 cannot figure out that the expressions are constant, and that > > triggers a build failure. Rewrite the expressions. > > > > The following gcc5 error is workaround: > > > > #define BM_PXP_CSC1_COEF0_YCBCR_MODE 0x80000000 > > ^ > > BM_PXP_CSC1_COEF0_YCBCR_MODE | > > ^ > > #define BM_PXP_CSC1_COEF0_YCBCR_MODE 0x80000000 > > ^ > > > > drivers/media/platform/nxp/imx-pxp.c: In function 'pxp_setup_csc': > > drivers/media/platform/nxp/imx-pxp.h:582:38: error: initializer element is not constant > > drivers/media/platform/nxp/imx-pxp.c:374:4: note: in expansion of macro 'BM_PXP_CSC1_COEF0_YCBCR_MODE' > > drivers/media/platform/nxp/imx-pxp.h:582:38: note: (near initialization for 'csc1_coef_bt601_lim[0]') > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> > > Can you elaborate on how this is triggered? Building the driver with https://cdn.kernel.org/pub/tools/crosstool/files/bin/x86_64/5.5.0/ It might be easier to repro with: ribalda@denia:~/work/linux$ podman run --pids-limit=-1 --rm -it -v .:/workdir registry.freedesktop.org/linux-media/media-ci/build-ancient # cd /workdir # CROSS_COMPILE=x86_64-linux- make allyesconfig # scripts/config -d MITIGATION_RETPOLINE # CROSS_COMPILE=x86_64-linux- make olddefconfig # CROSS_COMPILE=x86_64-linux- make drivers/media/platform/nxp/ > > At least I couldn't reproduce this by just copy & pasting the > csc1_coef_bt601_lim initializer and the required macros into gcc 5.4 on > godbolt. > > Can this be fixed by using GENMASK / FIELD_PREP instead? I was looking to make the change as simple as possible :) > > regards > Philipp
diff --git a/drivers/media/platform/nxp/imx-pxp.h b/drivers/media/platform/nxp/imx-pxp.h index 44f95c749d2e..ae4c6021c156 100644 --- a/drivers/media/platform/nxp/imx-pxp.h +++ b/drivers/media/platform/nxp/imx-pxp.h @@ -594,12 +594,17 @@ (((v) << 18) & BM_PXP_CSC1_COEF0_C0) #define BP_PXP_CSC1_COEF0_UV_OFFSET 9 #define BM_PXP_CSC1_COEF0_UV_OFFSET 0x0003FE00 + +/* + * We use v * (1 << 9) instead of v << 9, to workaround a gcc5 bug. + * The compiler cannot understand that the expression is constant. +*/ #define BF_PXP_CSC1_COEF0_UV_OFFSET(v) \ - (((v) << 9) & BM_PXP_CSC1_COEF0_UV_OFFSET) + (((v) * (1 << 9)) & BM_PXP_CSC1_COEF0_UV_OFFSET) #define BP_PXP_CSC1_COEF0_Y_OFFSET 0 #define BM_PXP_CSC1_COEF0_Y_OFFSET 0x000001FF #define BF_PXP_CSC1_COEF0_Y_OFFSET(v) \ - (((v) << 0) & BM_PXP_CSC1_COEF0_Y_OFFSET) + ((v) & BM_PXP_CSC1_COEF0_Y_OFFSET) #define HW_PXP_CSC1_COEF1 (0x000001b0)
GCC5 cannot figure out that the expressions are constant, and that triggers a build failure. Rewrite the expressions. The following gcc5 error is workaround: #define BM_PXP_CSC1_COEF0_YCBCR_MODE 0x80000000 ^ BM_PXP_CSC1_COEF0_YCBCR_MODE | ^ #define BM_PXP_CSC1_COEF0_YCBCR_MODE 0x80000000 ^ drivers/media/platform/nxp/imx-pxp.c: In function 'pxp_setup_csc': drivers/media/platform/nxp/imx-pxp.h:582:38: error: initializer element is not constant drivers/media/platform/nxp/imx-pxp.c:374:4: note: in expansion of macro 'BM_PXP_CSC1_COEF0_YCBCR_MODE' drivers/media/platform/nxp/imx-pxp.h:582:38: note: (near initialization for 'csc1_coef_bt601_lim[0]') Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> --- While implementing media-ci, we have found this build error with gcc5. --- drivers/media/platform/nxp/imx-pxp.h | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- base-commit: 6aa082910445aec6b1dc652a69c5178a555d8ca5 change-id: 20240628-gcc5-71a968c78e98 Best regards,