From a0329760807cff4b698bbe10884c3cbf014a7309 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Fri, 12 Jan 2024 00:40:36 +0000 Subject: [PATCH 1/2] media: mxl5xx: Move xpt structures off stack When building for LoongArch with clang 18.0.0, the stack usage of probe() is larger than the allowed 2048 bytes: drivers/media/dvb-frontends/mxl5xx.c:1698:12: warning: stack frame size (2368) exceeds limit (2048) in 'probe' [-Wframe-larger-than] 1698 | static int probe(struct mxl *state, struct mxl5xx_cfg *cfg) | ^ 1 warning generated. This is the result of the linked LLVM commit, which changes how the arrays of structures in config_ts() get handled with CONFIG_INIT_STACK_ZERO and CONFIG_INIT_STACK_PATTERN, which causes the above warning in combination with inlining, as config_ts() gets inlined into probe(). This warning can be easily fixed by moving the array of structures off of the stackvia 'static const', which is a better location for these variables anyways because they are static data that is only ever read from, never modified, so allocating the stack space is wasteful. This drops the stack usage from 2368 bytes to 256 bytes with the same compiler and configuration. Link: https://lore.kernel.org/linux-media/20240111-dvb-mxl5xx-move-structs-off-stack-v1-1-ca4230e67c11@kernel.org Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/1977 Link: https://github.com/llvm/llvm-project/commit/afe8b93ffdfef5d8879e1894b9d7dda40dee2b8d Signed-off-by: Nathan Chancellor Reviewed-by: Miguel Ojeda Tested-by: Miguel Ojeda Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb-frontends/mxl5xx.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/drivers/media/dvb-frontends/mxl5xx.c b/drivers/media/dvb-frontends/mxl5xx.c index ca1f1d3d6122..930da176e5bf 100644 --- a/drivers/media/dvb-frontends/mxl5xx.c +++ b/drivers/media/dvb-frontends/mxl5xx.c @@ -1381,57 +1381,57 @@ static int config_ts(struct mxl *state, enum MXL_HYDRA_DEMOD_ID_E demod_id, u32 nco_count_min = 0; u32 clk_type = 0; - struct MXL_REG_FIELD_T xpt_sync_polarity[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_sync_polarity[MXL_HYDRA_DEMOD_MAX] = { {0x90700010, 8, 1}, {0x90700010, 9, 1}, {0x90700010, 10, 1}, {0x90700010, 11, 1}, {0x90700010, 12, 1}, {0x90700010, 13, 1}, {0x90700010, 14, 1}, {0x90700010, 15, 1} }; - struct MXL_REG_FIELD_T xpt_clock_polarity[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_clock_polarity[MXL_HYDRA_DEMOD_MAX] = { {0x90700010, 16, 1}, {0x90700010, 17, 1}, {0x90700010, 18, 1}, {0x90700010, 19, 1}, {0x90700010, 20, 1}, {0x90700010, 21, 1}, {0x90700010, 22, 1}, {0x90700010, 23, 1} }; - struct MXL_REG_FIELD_T xpt_valid_polarity[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_valid_polarity[MXL_HYDRA_DEMOD_MAX] = { {0x90700014, 0, 1}, {0x90700014, 1, 1}, {0x90700014, 2, 1}, {0x90700014, 3, 1}, {0x90700014, 4, 1}, {0x90700014, 5, 1}, {0x90700014, 6, 1}, {0x90700014, 7, 1} }; - struct MXL_REG_FIELD_T xpt_ts_clock_phase[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_ts_clock_phase[MXL_HYDRA_DEMOD_MAX] = { {0x90700018, 0, 3}, {0x90700018, 4, 3}, {0x90700018, 8, 3}, {0x90700018, 12, 3}, {0x90700018, 16, 3}, {0x90700018, 20, 3}, {0x90700018, 24, 3}, {0x90700018, 28, 3} }; - struct MXL_REG_FIELD_T xpt_lsb_first[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_lsb_first[MXL_HYDRA_DEMOD_MAX] = { {0x9070000C, 16, 1}, {0x9070000C, 17, 1}, {0x9070000C, 18, 1}, {0x9070000C, 19, 1}, {0x9070000C, 20, 1}, {0x9070000C, 21, 1}, {0x9070000C, 22, 1}, {0x9070000C, 23, 1} }; - struct MXL_REG_FIELD_T xpt_sync_byte[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_sync_byte[MXL_HYDRA_DEMOD_MAX] = { {0x90700010, 0, 1}, {0x90700010, 1, 1}, {0x90700010, 2, 1}, {0x90700010, 3, 1}, {0x90700010, 4, 1}, {0x90700010, 5, 1}, {0x90700010, 6, 1}, {0x90700010, 7, 1} }; - struct MXL_REG_FIELD_T xpt_enable_output[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_enable_output[MXL_HYDRA_DEMOD_MAX] = { {0x9070000C, 0, 1}, {0x9070000C, 1, 1}, {0x9070000C, 2, 1}, {0x9070000C, 3, 1}, {0x9070000C, 4, 1}, {0x9070000C, 5, 1}, {0x9070000C, 6, 1}, {0x9070000C, 7, 1} }; - struct MXL_REG_FIELD_T xpt_err_replace_sync[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_err_replace_sync[MXL_HYDRA_DEMOD_MAX] = { {0x9070000C, 24, 1}, {0x9070000C, 25, 1}, {0x9070000C, 26, 1}, {0x9070000C, 27, 1}, {0x9070000C, 28, 1}, {0x9070000C, 29, 1}, {0x9070000C, 30, 1}, {0x9070000C, 31, 1} }; - struct MXL_REG_FIELD_T xpt_err_replace_valid[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_err_replace_valid[MXL_HYDRA_DEMOD_MAX] = { {0x90700014, 8, 1}, {0x90700014, 9, 1}, {0x90700014, 10, 1}, {0x90700014, 11, 1}, {0x90700014, 12, 1}, {0x90700014, 13, 1}, {0x90700014, 14, 1}, {0x90700014, 15, 1} }; - struct MXL_REG_FIELD_T xpt_continuous_clock[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_continuous_clock[MXL_HYDRA_DEMOD_MAX] = { {0x907001D4, 0, 1}, {0x907001D4, 1, 1}, {0x907001D4, 2, 1}, {0x907001D4, 3, 1}, {0x907001D4, 4, 1}, {0x907001D4, 5, 1}, {0x907001D4, 6, 1}, {0x907001D4, 7, 1} }; - struct MXL_REG_FIELD_T xpt_nco_clock_rate[MXL_HYDRA_DEMOD_MAX] = { + static const struct MXL_REG_FIELD_T xpt_nco_clock_rate[MXL_HYDRA_DEMOD_MAX] = { {0x90700044, 16, 80}, {0x90700044, 16, 81}, {0x90700044, 16, 82}, {0x90700044, 16, 83}, {0x90700044, 16, 84}, {0x90700044, 16, 85}, From 3a2f7cc55f073bc8c1dc60a21eb9ff5e5da14af4 Mon Sep 17 00:00:00 2001 From: Ricardo Ribalda Date: Thu, 6 Jun 2024 13:16:35 +0000 Subject: [PATCH 2/2] media: dvb-frontend/mxl5xx: Refactor struct MBIN_FILE_T and MBIN_SEGMENT_T Replace the older style one-element array with a flexible array member. There does not seem to be any allocation for these structs in the code, so no more code changes are required. The following cocci warnings are fixed: drivers/media/dvb-frontends/mxl5xx_defs.h:182:4-8: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays) drivers/media/dvb-frontends/mxl5xx_defs.h:171:4-8: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays) Signed-off-by: Ricardo Ribalda Signed-off-by: Hans Verkuil --- drivers/media/dvb-frontends/mxl5xx_defs.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/media/dvb-frontends/mxl5xx_defs.h b/drivers/media/dvb-frontends/mxl5xx_defs.h index 097271f73740..bf08d82ba2cc 100644 --- a/drivers/media/dvb-frontends/mxl5xx_defs.h +++ b/drivers/media/dvb-frontends/mxl5xx_defs.h @@ -168,7 +168,7 @@ struct MBIN_FILE_HEADER_T { struct MBIN_FILE_T { struct MBIN_FILE_HEADER_T header; - u8 data[1]; + u8 data[]; }; struct MBIN_SEGMENT_HEADER_T { @@ -179,7 +179,7 @@ struct MBIN_SEGMENT_HEADER_T { struct MBIN_SEGMENT_T { struct MBIN_SEGMENT_HEADER_T header; - u8 data[1]; + u8 data[]; }; enum MXL_CMD_TYPE_E { MXL_CMD_WRITE = 0, MXL_CMD_READ };