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Commit 3cf27234 authored by David Brownell's avatar David Brownell Committed by Greg Kroah-Hartman
Browse files

USB: at91_udc can prefetch data 



The at91sam9 chip are ARMv5 so they support preload instructions.
Use preloading to load the FIFO a bit faster.

Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent a89a2cd3

drivers/usb/gadget/at91_udc.c

+4 −1
Original line number Diff line number Diff line
@@ -389,6 +389,7 @@ static int write_fifo(struct at91_ep *ep, struct at91_request *req) 
	u32		csr = __raw_readl(creg);

	u8 __iomem	*dreg = ep->creg + (AT91_UDP_FDR(0) - AT91_UDP_CSR(0));

	unsigned	total, count, is_last;

	u8		*buf;



	/*

	 * TODO: allow for writing two packets to the fifo ... that'll
@@ -413,6 +414,8 @@ static int write_fifo(struct at91_ep *ep, struct at91_request *req) 
			return 0;

	}



	buf = req->req.buf + req->req.actual;

	prefetch(buf);

	total = req->req.length - req->req.actual;

	if (ep->ep.maxpacket < total) {

		count = ep->ep.maxpacket;
@@ -435,7 +438,7 @@ static int write_fifo(struct at91_ep *ep, struct at91_request *req) 
	 * recover when the actual bytecount matters (e.g. for USB Test

	 * and Measurement Class devices).

	 */

	__raw_writesb(dreg, req->req.buf + req->req.actual, count);

	__raw_writesb(dreg, buf, count);

	csr &= ~SET_FX;

	csr |= CLR_FX | AT91_UDP_TXPKTRDY;

	__raw_writel(csr, creg);