| Message ID | 20250415075659.428549-1-m.szyprowski@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | dma-mapping: avoid potential unused data compilation warning | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
On Tue, Apr 15, 2025 at 09:56:59AM +0200, Marek Szyprowski wrote: > When CONFIG_NEED_DMA_MAP_STATE is not defined, dma-mapping clients might > report unused data compilation warnings for dma_unmap_*() calls > arguments. Redefine macros for those calls to let compiler to notice that > it is okay when the provided arguments are not used. Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> (GCC on default i386_defconfig with `make W=1` on v6.15-rc2)
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index b79925b1c433..85ab710ec0e7 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -629,10 +629,14 @@ static inline int dma_mmap_wc(struct device *dev, #else #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME) #define DEFINE_DMA_UNMAP_LEN(LEN_NAME) -#define dma_unmap_addr(PTR, ADDR_NAME) (0) -#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) do { } while (0) -#define dma_unmap_len(PTR, LEN_NAME) (0) -#define dma_unmap_len_set(PTR, LEN_NAME, VAL) do { } while (0) +#define dma_unmap_addr(PTR, ADDR_NAME) \ + ({ typeof(PTR) __p __maybe_unused = PTR; 0; }) +#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) \ + do { typeof(PTR) __p __maybe_unused = PTR; } while (0) +#define dma_unmap_len(PTR, LEN_NAME) \ + ({ typeof(PTR) __p __maybe_unused = PTR; 0; }) +#define dma_unmap_len_set(PTR, LEN_NAME, VAL) \ + do { typeof(PTR) __p __maybe_unused = PTR; } while (0) #endif #endif /* _LINUX_DMA_MAPPING_H */
When CONFIG_NEED_DMA_MAP_STATE is not defined, dma-mapping clients might report unused data compilation warnings for dma_unmap_*() calls arguments. Redefine macros for those calls to let compiler to notice that it is okay when the provided arguments are not used. Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> --- include/linux/dma-mapping.h | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-)