Re: [PATCH 6/6] [RFC] usb: gadget: USB_GADGET should depend on HAS_DMA

[Geert Uytterhoeven]

Hi Alan,

On Thu, Jul 11, 2013 at 5:51 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> On Thu, 11 Jul 2013, Geert Uytterhoeven wrote:
>
>> If NO_DMA=y:
>>
>> drivers/built-in.o: In function `dma_set_coherent_mask':
>> include/linux/dma-mapping.h:93: undefined reference to `dma_supported'
>> include/linux/dma-mapping.h:93: undefined reference to `dma_supported'
>> drivers/built-in.o: In function `usb_gadget_unmap_request':
>> drivers/usb/gadget/udc-core.c:91: undefined reference to `dma_unmap_sg'
>> drivers/usb/gadget/udc-core.c:96: undefined reference to `dma_unmap_single'
>> drivers/built-in.o: In function `usb_gadget_map_request':
>> drivers/usb/gadget/udc-core.c:62: undefined reference to `dma_map_sg'
>> drivers/usb/gadget/udc-core.c:71: undefined reference to `dma_map_single'
>> drivers/usb/gadget/udc-core.c:74: undefined reference to `dma_mapping_error'
>>
>> Signed-off-by: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
>> ---
>> This one is very debatable: probably the parts using the DMA API should
>> be factored out, instead of disabling the whole USB gadget subsystem.
>
> Indeed.  How does this look instead?
>
> Alan Stern
>
>
>
> Index: usb-3.10/drivers/usb/gadget/udc-core.c
> ===================================================================
> --- usb-3.10.orig/drivers/usb/gadget/udc-core.c
> +++ usb-3.10/drivers/usb/gadget/udc-core.c
> @@ -50,6 +50,8 @@ static DEFINE_MUTEX(udc_lock);
>
>  /* ------------------------------------------------------------------------- */
>
> +#ifdef CONFIG_HAS_DMA
> +
>  int usb_gadget_map_request(struct usb_gadget *gadget,
>                 struct usb_request *req, int is_in)
>  {
> @@ -99,6 +101,8 @@ void usb_gadget_unmap_request(struct usb
>  }
>  EXPORT_SYMBOL_GPL(usb_gadget_unmap_request);
>
> +#endif /* CONFIG_HAS_DMA */
> +
>  /* ------------------------------------------------------------------------- */
>
>  void usb_gadget_set_state(struct usb_gadget *gadget,
> @@ -194,9 +198,11 @@ int usb_add_gadget_udc_release(struct de
>         dev_set_name(&gadget->dev, "gadget");
>         gadget->dev.parent = parent;
>
> +#ifdef CONFIG_HAS_DMA
>         dma_set_coherent_mask(&gadget->dev, parent->coherent_dma_mask);
>         gadget->dev.dma_parms = parent->dma_parms;
>         gadget->dev.dma_mask = parent->dma_mask;
> +#endif
>
>         if (release)
>                 gadget->dev.release = release;

Thanks, that works!

(after adding a few more dependencies on HAS_DMA for drivers that call
into usb_gadget_{,un}map_request() and/or dma_set_coherent_mask(),
for which I'll send separate patches).

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
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