[U-Boot] [PATCH 2/6] usb:udc:samsung: Remove redundant cache operation from Samsung UDC driver

[Lukasz Majewski]

A set of cache operations (both invalidation and flush) were redundant
in the S3C HS OTG Samsung driver.

Test condition
- test HW + measurement: Trats - Exynos4210 rev.1
- test HW Trats2 - Exynos4412 rev.1
400 MiB compressed rootfs image download with `thor 0 mmc 0`

Measurements:

Base values (without improvement):
Transmission speed: 9.51 MiB/s

After the change:
Transmission speed: 10.15 MiB/s

Change-Id: I0d55da4de724b14e988fefdb37a012562f7da8a2
Signed-off-by: Lukasz Majewski <l.majewski at samsung.com>
Cc: Marek Vasut <marex at denx.de>
---
 drivers/usb/gadget/s3c_udc_otg_xfer_dma.c |   13 -------------
 1 file changed, 13 deletions(-)

diff --git a/drivers/usb/gadget/s3c_udc_otg_xfer_dma.c b/drivers/usb/gadget/s3c_udc_otg_xfer_dma.c
index 1cbf8f6..eaa3a20 100644
--- a/drivers/usb/gadget/s3c_udc_otg_xfer_dma.c
+++ b/drivers/usb/gadget/s3c_udc_otg_xfer_dma.c
@@ -29,10 +29,6 @@ static inline void s3c_udc_ep0_zlp(struct s3c_udc *dev)
 {
 	u32 ep_ctrl;
 
-	flush_dcache_range((unsigned long) usb_ctrl_dma_addr,
-			   (unsigned long) usb_ctrl_dma_addr
-			   + DMA_BUFFER_SIZE);
-
 	writel(usb_ctrl_dma_addr, &reg->in_endp[EP0_CON].diepdma);
 	writel(DIEPT_SIZ_PKT_CNT(1), &reg->in_endp[EP0_CON].dieptsiz);
 
@@ -52,10 +48,6 @@ void s3c_udc_pre_setup(void)
 	debug_cond(DEBUG_IN_EP,
 		   "%s : Prepare Setup packets.\n", __func__);
 
-	invalidate_dcache_range((unsigned long) usb_ctrl_dma_addr,
-				(unsigned long) usb_ctrl_dma_addr
-				+ DMA_BUFFER_SIZE);
-
 	writel(DOEPT_SIZ_PKT_CNT(1) | sizeof(struct usb_ctrlrequest),
 	       &reg->out_endp[EP0_CON].doeptsiz);
 	writel(usb_ctrl_dma_addr, &reg->out_endp[EP0_CON].doepdma);
@@ -115,11 +107,6 @@ static int setdma_rx(struct s3c_ep *ep, struct s3c_request *req)
 	ep->len = length;
 	ep->dma_buf = buf;
 
-	invalidate_dcache_range((unsigned long) ep->dev->dma_buf[ep_num],
-				(unsigned long) ep->dev->dma_buf[ep_num]
-				+ ROUND(ep->ep.maxpacket,
-					CONFIG_SYS_CACHELINE_SIZE));
-
 	if (length == 0)
 		pktcnt = 1;
 	else
-- 
1.7.10.4