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SubjectRe: [PATCH] ioatdma: silence GCC warnings
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On Mon, Jun 17, 2013 at 3:35 AM, Paul Bolle <pebolle@tiscali.nl> wrote:
> Building dma_v3.o triggers two GCC warnings:
> drivers/dma/ioat/dma_v3.c: In function ‘__ioat3_prep_pq16_lock’:
> drivers/dma/ioat/dma_v3.c:264:11: warning: array subscript is below array bounds [-Warray-bounds]
> drivers/dma/ioat/dma_v3.c:264:11: warning: array subscript is below array bounds [-Warray-bounds]
>
> These warnings are caused by pq16_set_src(). It uses "int idx" as an
> index to an eight element array. Changing "idx" to unsigned int silences
> these warnings. Apparently GCC can then determine that "idx" will never
> be negative.
>
> Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
> ---

Seems this is fixed in gcc as of 4.7.2, but we can make things quieter
for build testers on older compilers.

> 0) Compile tested only.
>
> 1) These warning were introduced in v3.10-rc1. That must have been
> through commit 7727eaa449 ("ioatdma: Adding support for 16 src PQ ops
> and super extended descriptors").
>
> drivers/dma/ioat/dma_v3.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/dma/ioat/dma_v3.c b/drivers/dma/ioat/dma_v3.c
> index ca6ea9b..b5102da 100644
> --- a/drivers/dma/ioat/dma_v3.c
> +++ b/drivers/dma/ioat/dma_v3.c
> @@ -251,7 +251,7 @@ static bool is_bwd_noraid(struct pci_dev *pdev)
> }
>
> static void pq16_set_src(struct ioat_raw_descriptor *desc[3],
> - dma_addr_t addr, u32 offset, u8 coef, int idx)
> + dma_addr_t addr, u32 offset, u8 coef, unsigned int idx)

"unsigned int" --> "unsigned"

> {
> struct ioat_pq_descriptor *pq = (struct ioat_pq_descriptor *)desc[0];
> struct ioat_pq16a_descriptor *pq16 =

Just do this hunk as the minimal one line change.
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