[U-Boot] [PATCH V2 RESEND] nand: fix buffer alignment in new verification feature

[Heiko Schocher]

Hello Stephen,

Am 06.05.2015 18:01, schrieb Stephen Warren:
> From: Stephen Warren <swarren at nvidia.com>
>
> On systems with caches enabled, NAND I/O may need to flush/invalidate
> the cache during read/write operations. For this to work correctly, all
> buffers must be cache-aligned. Fix nand_verify*() to allocate aligned
> buffers.
>
> This prevents cache alignment warnings from being spewed when using
> U-Boot to write an updated version of itself to flash on NVIDIA Tegra
> Seaboard (after perturbation of stack/data layout in current
> u-boot-dm/next branch).
>
> I have validatd (executed) nand_verify(), but I don't think I've executed
> nand_verify_page_oob(); testing of that would be useful.
>
> Cc: Peter Tyser <ptyser at xes-inc.com>
> Cc: Heiko Schocher <hs at denx.de>
> Cc: Scott Wood <scottwood at freescale.com>
> Fixes: 59b5a2ad83df ("nand: Add verification functions")
> Signed-off-by: Stephen Warren <swarren at nvidia.com>
> Reviewed-by: Simon Glass <sjg at chromium.org>
> Acked-by: Scott Wood <scottwood at freescale.com>
> ---
> Resending to Tom for direct application, including reviewed-/acked-by tags
> from others.
>
> As an aside, I think this patch demonstrates why new features shouldn't be
> merged just a couple weeks before the release; there's not enough time to
> detect regressions and patch them. The merge window is for new features.

Yes, with new features we should be more conservative.

> v2: Use memalign() rather than ALLOC_CACHE_ALIGN_BUFFER() so that the
> buffer is allocated from the heap not on the stack, to reduce stack
> usage.
>
>   drivers/mtd/nand/nand_util.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)

Thanks for detecting this.

Acked-by: Heiko Schocher <hs at denx.de>

bye,
Heiko
>
> diff --git a/drivers/mtd/nand/nand_util.c b/drivers/mtd/nand/nand_util.c
> index 12dd26a33fac..ee2c24df3b85 100644
> --- a/drivers/mtd/nand/nand_util.c
> +++ b/drivers/mtd/nand/nand_util.c
> @@ -483,7 +483,7 @@ int nand_verify_page_oob(nand_info_t *nand, struct mtd_oob_ops *ops, loff_t ofs)
>
>   	memcpy(&vops, ops, sizeof(vops));
>
> -	vops.datbuf = malloc(verlen);
> +	vops.datbuf = memalign(ARCH_DMA_MINALIGN, verlen);
>
>   	if (!vops.datbuf)
>   		return -ENOMEM;
> @@ -520,7 +520,7 @@ int nand_verify(nand_info_t *nand, loff_t ofs, size_t len, u_char *buf)
>   	int rval = 0;
>   	size_t verofs;
>   	size_t verlen = nand->writesize;
> -	uint8_t *verbuf = malloc(verlen);
> +	uint8_t *verbuf = memalign(ARCH_DMA_MINALIGN, verlen);
>
>   	if (!verbuf)
>   		return -ENOMEM;
>

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