Re: [PATCH] usb: gadget: s3c-hsotg: Mark s3c_hsotg_map_dma()/s3c_hsotg_unmap_dma() inline

From: Bartlomiej Zolnierkiewicz
Date: Tue May 06 2014 - 14:08:14 EST



Hi,

On Tuesday, May 06, 2014 07:37:01 PM Geert Uytterhoeven wrote:
> If NO_DMA=y, depending on the gcc version:
>
> drivers/built-in.o: In function `s3c_hsotg_map_dma':
> s3c-hsotg.c:(.text+0x375b2c): undefined reference to `usb_gadget_map_request'
> drivers/built-in.o: In function `s3c_hsotg_unmap_dma':
> s3c-hsotg.c:(.text+0x376a32): undefined reference to `usb_gadget_unmap_request'
> make[3]: *** [vmlinux] Error 1
>
> The obvious fix of making USB_S3C_HSOTG depend on HAS_DMA is a bit overkill,
> as DMA is never actually used. All (two) calls to s3c_hsotg_map_dma() and
> s3c_hsotg_unmap_dma() are protected by a call into the using_dma() checking
> function, which always returns false:
>
> static inline bool using_dma(struct s3c_hsotg *hsotg)
> {
> return false; /* support is not complete */
> }
>
> Due to the constant return value, gcc optimizes away the calls to
> s3c_hsotg_map_dma() and s3c_hsotg_unmap_dma(). But some versions of gcc
> (e.g. 4.1.2) still emit the functions themselves, causing link errors.
>
> Marking s3c_hsotg_map_dma()/s3c_hsotg_unmap_dma() inline fixes this.

How's about just removing the dead code instead? It has never worked since
the driver introduction back in June 2009 (almost 5 years) and it is trivial
to bring it back from kernel git repository if needed in the future.

PS Could you please fix -next kernels as well (drivers/usb/gadget/s3c-hsotg.c
has moved to drivers/usb/dwc2/gadget.c recently)?

> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> ---
> This replaces "[PATCH/RFC] usb: gadget: CONFIG_USB_S3C_HSOTG should depend on
> HAS_DMA"
>
> drivers/usb/gadget/s3c-hsotg.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/usb/gadget/s3c-hsotg.c b/drivers/usb/gadget/s3c-hsotg.c
> index 2a9cb674926a..2740042228a4 100644
> --- a/drivers/usb/gadget/s3c-hsotg.c
> +++ b/drivers/usb/gadget/s3c-hsotg.c
> @@ -437,9 +437,9 @@ static inline int is_ep_periodic(struct s3c_hsotg_ep *hs_ep)
> * This is the reverse of s3c_hsotg_map_dma(), called for the completion
> * of a request to ensure the buffer is ready for access by the caller.
> */
> -static void s3c_hsotg_unmap_dma(struct s3c_hsotg *hsotg,
> - struct s3c_hsotg_ep *hs_ep,
> - struct s3c_hsotg_req *hs_req)
> +static inline void s3c_hsotg_unmap_dma(struct s3c_hsotg *hsotg,
> + struct s3c_hsotg_ep *hs_ep,
> + struct s3c_hsotg_req *hs_req)
> {
> struct usb_request *req = &hs_req->req;
>
> @@ -861,9 +861,9 @@ static void s3c_hsotg_start_req(struct s3c_hsotg *hsotg,
> * DMA memory, then we map the memory and mark our request to allow us to
> * cleanup on completion.
> */
> -static int s3c_hsotg_map_dma(struct s3c_hsotg *hsotg,
> - struct s3c_hsotg_ep *hs_ep,
> - struct usb_request *req)
> +static inline int s3c_hsotg_map_dma(struct s3c_hsotg *hsotg,
> + struct s3c_hsotg_ep *hs_ep,
> + struct usb_request *req)
> {
> struct s3c_hsotg_req *hs_req = our_req(req);
> int ret;

Best regards,
--
Bartlomiej Zolnierkiewicz
Samsung R&D Institute Poland
Samsung Electronics

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