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94963138cc
The descriptor FIFO requires that all words of a descriptor are written in order, with the control word written last to flush it into the DMA engine. Using memcpy() with __force to __iomem is not the correct API and does not guarantee appropriate MMIO access on all architectures. Replace the descriptor body copy with memcpy_toio(), using offsetof(struct msgdma_extended_desc, control) to exclude the control word. This matches the previous sizeof(desc->hw_desc) - sizeof(u32) length only when control is the last struct member; add a static_assert to enforce that layout so a future field after control cannot silently break FIFO ordering. Keep writing the control word separately with write barriers, so it remains the final word pushed into the FIFO. Signed-off-by: Adrian Ng Ho Yin <adrianhoyin.ng@altera.com> Signed-off-by: Tze Yee Ng <tze.yee.ng@altera.com> Link: https://patch.msgid.link/f6f3b4a2e2eb0eb1a51976de3f5d1ef5bab9bd76.1779697226.git.tze.yee.ng@altera.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
969 lines
26 KiB
969 lines
26 KiB