Subject: [PATCH V2 3/6] spi/spi-pl022: Don't allocate more sg than required.

From: [email-masked] (Sergei Shtylyov)
Date: Wed, 10 Aug 2011 15:42:46 +0400

Hello.

On 10-08-2011 12:50, Viresh Kumar wrote:

> In routine configure_dma(), if transfer->len = PAGE_SIZE, then pages is one more
> than required. While leads to one more sg getting allocated.

> This is wrong. Correct this to allocate correct number of sg.

> Signed-off-by: Viresh Kumar<[email-masked]>
> Tested-by: Linus Walleij<[email-masked]>
> ---
>   drivers/spi/spi-pl022.c |    3 ++-
>   1 files changed, 2 insertions(+), 1 deletions(-)

> diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c
> index 80116be..1c8b9ec 100644
> --- a/drivers/spi/spi-pl022.c
> +++ b/drivers/spi/spi-pl022.c
> @@ -1016,7 +1016,8 @@ static int configure_dma(struct pl022 *pl022)
>   	dmaengine_slave_config(txchan,&tx_conf);
>
>   	/* Create sglists for the transfers */
> -	pages = (pl022->cur_transfer->len>>  PAGE_SHIFT) + 1;
> +	pages = ((pl022->cur_transfer->len + (1 << PAGE_SHIFT) - 1)
> +			>>  PAGE_SHIFT);

    No need for parens around the rvalue.

WBR, Sergei