Re: [PATCH net] gve: DQO: Suppress unused var warnings
flat view
From: Arnd Bergmann <arnd@kernel.org>
Date: 2021-09-28 14:15:26
On Tue, Sep 28, 2021 at 2:00 AM Bailey Forrest [off-list ref] wrote:
On Mon, Sep 27, 2021 at 4:21 PM Jakub Kicinski [off-list ref] wrote:quoted
On Mon, 27 Sep 2021 13:21:30 -0700 Bailey Forrest wrote: Looks like fixing this on the wrong end, dma_unmap_len_set() and friends should always evaluate their arguments.That makes sense. Arnd, if you want to fix this inside of the dma_* macros, the following diff resolves the errors reported for this driver:
quoted hunk ↗ jump to hunk
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index dca2b1355bb1..f51eee0f678e 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h@@ -590,10 +590,21 @@ 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) ({ (void)PTR; 0; }) + +#define dma_unmap_addr_set(PTR, ADDR_NAME, VAL) do { \
Unfortunately, this breaks every other driver using these macros, as the
point of them is that the unmap-address is not actually defined
and not taking up space in data structure. Referencing it by name
is a compile-time bug.
I've come up with a new patch to gve that just removes the
"struct gve_tx_dma_buf" and open-codes the access everywhere,
sending that as v2 now. Feel free to take that and modify as needed
before sending on, or doing yet another patch.
Arnd