usb: add a hcd_uses_dma helper

The USB buffer allocation code is the only place in the usb core (and in fact the whole kernel) that uses is_device_dma_capable, while the URB mapping code uses the uses_dma flag in struct usb_bus. Switch the buffer allocation to use the uses_dma flag used by the rest of the USB code, and create a helper in hcd.h that checks this flag as well as the CONFIG_HAS_DMA to simplify the caller a bit.

Christoph Hellwig committed 7 years ago

Commit edfbcb31 parent dd3ecf15 files · +10 −11Browse files

Showing the changes to include/linux/usb (1 of 5 files). Show all

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include/linux/usb/hcd.h+3−0

@@ -422,6 +422,9 @@ static inline bool hcd_periodic_completion_in_progress(struct usb_hcd *hcd, · 421 unmodified lines
422	422	return hcd->high_prio_bh.completing_ep == ep;
423	423	}
424	424
	425	+#define hcd_uses_dma(hcd) \
	426	+ (IS_ENABLED(CONFIG_HAS_DMA) && (hcd)->self.uses_dma)
	427	+
425	428	extern int usb_hcd_link_urb_to_ep(struct usb_hcd hcd, struct urb urb);
426	429	extern int usb_hcd_check_unlink_urb(struct usb_hcd hcd, struct urb urb,
427	430	int status);