[PATCH] mtd: nand: sh_flctl: handle dma_submit() errors

[PATCH] mtd: nand: sh_flctl: handle dma_submit() errors

[Brian Norris]

Some build tools noticed that 'cookie' is being set but not used. Might
as well catch the errors here and handle them the same way we handle
other DMA prep steps.

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
Compile tested only

 drivers/mtd/nand/sh_flctl.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/mtd/nand/sh_flctl.c b/drivers/mtd/nand/sh_flctl.c
index 6fa3bcd59769..442ce619b3b6 100644
--- a/drivers/mtd/nand/sh_flctl.c
+++ b/drivers/mtd/nand/sh_flctl.c
@@ -397,7 +397,7 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl *flctl, unsigned long *buf,
 	struct dma_chan *chan;
 	enum dma_transfer_direction tr_dir;
 	dma_addr_t dma_addr;
-	dma_cookie_t cookie = -EINVAL;
+	dma_cookie_t cookie;
 	uint32_t reg;
 	int ret;
 
@@ -423,6 +423,12 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl *flctl, unsigned long *buf,
 		desc->callback = flctl_dma_complete;
 		desc->callback_param = flctl;
 		cookie = dmaengine_submit(desc);
+		if (dma_submit_error(cookie)) {
+			ret = dma_submit_error(cookie);
+			dev_warn(&flctl->pdev->dev,
+				 "DMA submit failed, falling back to PIO\n");
+			goto out;
+		}
 
 		dma_async_issue_pending(chan);
 	} else {
-- 
2.8.0.rc3.226.g39d4020

Re: [PATCH] mtd: nand: sh_flctl: handle dma_submit() errors

[Boris Brezillon]

On Thu,  5 May 2016 12:42:44 -0700
Brian Norris <computersforpeace@gmail.com> wrote:

> Some build tools noticed that 'cookie' is being set but not used. Might
> as well catch the errors here and handle them the same way we handle
> other DMA prep steps.
> 

Applied. I know it's only been compile tested, and even if nobody
acked/reviewed/tested it, it seems to be correct.
Let's see if someone complains about a regression (the commit will be in
-next for the whole 4.8-rc cycle).

Thanks,

Boris

> Signed-off-by: Brian Norris <computersforpeace@gmail.com>
> ---
> Compile tested only
> 
>  drivers/mtd/nand/sh_flctl.c | 8 +++++++-
>  1 file changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mtd/nand/sh_flctl.c b/drivers/mtd/nand/sh_flctl.c
> index 6fa3bcd59769..442ce619b3b6 100644
> --- a/drivers/mtd/nand/sh_flctl.c
> +++ b/drivers/mtd/nand/sh_flctl.c
> @@ -397,7 +397,7 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl *flctl, unsigned long *buf,
>  	struct dma_chan *chan;
>  	enum dma_transfer_direction tr_dir;
>  	dma_addr_t dma_addr;
> -	dma_cookie_t cookie = -EINVAL;
> +	dma_cookie_t cookie;
>  	uint32_t reg;
>  	int ret;
>  
> @@ -423,6 +423,12 @@ static int flctl_dma_fifo0_transfer(struct sh_flctl *flctl, unsigned long *buf,
>  		desc->callback = flctl_dma_complete;
>  		desc->callback_param = flctl;
>  		cookie = dmaengine_submit(desc);
> +		if (dma_submit_error(cookie)) {
> +			ret = dma_submit_error(cookie);
> +			dev_warn(&flctl->pdev->dev,
> +				 "DMA submit failed, falling back to PIO\n");
> +			goto out;
> +		}
>  
>  		dma_async_issue_pending(chan);
>  	} else {