Subject: Re: [PATCH] usb: gadget: fsl_udc_core: remove mapped flag

From: Sergei Shtylyov <[email-masked]>
Date: Wed, 05 Sep 2012 16:31:51 +0400

Hello.

On 04-09-2012 21:24, Enrico Scholz wrote:

> The 'mapped' flag in 'struct fsl_req' flag is redundant with checking
> for 'req.dma != DMA_ADDR_INVALID' and it was also set to a wrong value
> (see 2nd hunk of patch).

> Replacing it in the way described above saves 60 bytes:

>    function                                     old     new   delta
>    fsl_udc_irq                                 2952    2940     -12
>    ep0_prime_status                             380     368     -12
>    done                                         448     432     -16
>    fsl_ep_queue                                 668     648     -20

> and has same (or less) runtime costs like evaluating 'req->mapped'.

> Signed-off-by: Enrico Scholz <[email-masked]>
> ---
>   drivers/usb/gadget/fsl_udc_core.c | 10 ++--------
>   drivers/usb/gadget/fsl_usb2_udc.h |  1 -
>   2 files changed, 2 insertions(+), 9 deletions(-)

> diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c
> index 55c4a61..1282a11 100644
> --- a/drivers/usb/gadget/fsl_udc_core.c
> +++ b/drivers/usb/gadget/fsl_udc_core.c
> @@ -195,14 +195,13 @@ static void done(struct fsl_ep *ep, struct fsl_req *req, int status)
>   		dma_pool_free(udc->td_pool, curr_td, curr_td->td_dma);
>   	}
>
> -	if (req->mapped) {
> +	if (req->req.dma != DMA_ADDR_INVALID) {
>   		dma_unmap_single(ep->udc->gadget.dev.parent,
>   			req->req.dma, req->req.length,
>   			ep_is_in(ep)
>   				? DMA_TO_DEVICE
>   				: DMA_FROM_DEVICE);
>   		req->req.dma = DMA_ADDR_INVALID;
> -		req->mapped = 0;
>   	} else
>   		dma_sync_single_for_cpu(ep->udc->gadget.dev.parent,
>   			req->req.dma, req->req.length,
> @@ -915,15 +914,12 @@ fsl_ep_queue(struct usb_ep *_ep, struct usb_request *_req, gfp_t gfp_flags)
>   					req->req.length, ep_is_in(ep)
>   						? DMA_TO_DEVICE
>   						: DMA_FROM_DEVICE);
> -		req->mapped = 1;
> -	} else {
> +	} else

    You should keep the { here, according to the Documentation/CodingStyle.
If one branch of the *if* statement uses {}, so should the other.

WBR, Sergei