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SubjectRe: [PATCH 1/4] mtd: sh_flctl: let flctl_dma_fifo0_transfer return 0 on success
Date
Hi Nicholas,

Thank you for the patch.

On Saturday 02 May 2015 09:57:07 Nicholas Mc Guire wrote:
> wait_for_completion_timeout() returns unsigned long not int so the check
> for <= should be == and the type unsigned long. With that fixup the return
> value of flctl_dma_fifo0_transfer can be changed to 0 for success. This
> changes the failure return value for wait_for_completion_timeout to
> -ETIMEDOUT and implicitly 0 on success by initializing ret to 0.
> The call-sites are fixed up to check for == 0 rather than > 0 as well.
>
> Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>

I would squash patches 3/4 and 4/4 into this one, there isn't much point in
having indentation fixes as separate patches when this one already touches the
same lines of code. Then,

Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>
> V2: As suggested by Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> the expected success return value is 0 so rather than just fixing up
> wait_for_completion_timeout return handling the return value of
> flctl_dma_fifo0_transfer should be adjusted.
>
> call sites:
> read_fiforeg,write_ec_fiforeg assume > 0 == success
> are fixed up to check for == 0 for success
> and the comment in flctl_dma_fifo0_transfe
> /* ret > 0 is success */
> return ret;
> is dropped since returning 0 on success is the expected.
>
> Patch was compile tested with ap325rxa_defconfig (implies
> CONFIG_MTD_NAND_SH_FLCTL=y)
>
> Patch is against 4.1-rc1 (localversion-next is -next-20150501)
>
> drivers/mtd/nand/sh_flctl.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/mtd/nand/sh_flctl.c b/drivers/mtd/nand/sh_flctl.c
> index c3ce81c..9b032dd 100644
> --- a/drivers/mtd/nand/sh_flctl.c
> +++ b/drivers/mtd/nand/sh_flctl.c
> @@ -353,7 +353,8 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl
> *flctl, unsigned long *buf, dma_addr_t dma_addr;
> dma_cookie_t cookie = -EINVAL;
> uint32_t reg;
> - int ret;
> + int ret = 0;
> + unsigned long time_left;
>
> if (dir == DMA_FROM_DEVICE) {
> chan = flctl->chan_fifo0_rx;
> @@ -388,13 +389,14 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl
> *flctl, unsigned long *buf, goto out;
> }
>
> - ret =
> + time_left =
> wait_for_completion_timeout(&flctl->dma_complete,
> msecs_to_jiffies(3000));
>
> - if (ret <= 0) {
> + if (time_left == 0) {
> dmaengine_terminate_all(chan);
> dev_err(&flctl->pdev->dev, "wait_for_completion_timeout\n");
> + ret = -ETIMEDOUT;
> }
>
> out:
> @@ -404,7 +406,6 @@ out:
>
> dma_unmap_single(chan->device->dev, dma_addr, len, dir);
>
> - /* ret > 0 is success */
> return ret;
> }
>
> @@ -428,7 +429,7 @@ static void read_fiforeg(struct sh_flctl *flctl, int
> rlen, int offset)
>
> /* initiate DMA transfer */
> if (flctl->chan_fifo0_rx && rlen >= 32 &&
> - flctl_dma_fifo0_transfer(flctl, buf, rlen, DMA_DEV_TO_MEM) > 0)
> + flctl_dma_fifo0_transfer(flctl, buf, rlen, DMA_DEV_TO_MEM) == 0)
> goto convert; /* DMA success */
>
> /* do polling transfer */
> @@ -487,7 +488,7 @@ static void write_ec_fiforeg(struct sh_flctl *flctl, int
> rlen,
>
> /* initiate DMA transfer */
> if (flctl->chan_fifo0_tx && rlen >= 32 &&
> - flctl_dma_fifo0_transfer(flctl, buf, rlen, DMA_MEM_TO_DEV) > 0)
> + flctl_dma_fifo0_transfer(flctl, buf, rlen, DMA_MEM_TO_DEV) == 0)
> return; /* DMA success */
>
> /* do polling transfer */

--
Regards,

Laurent Pinchart



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