From: David Brownell <dbrownell@users.sourceforge.net>
Date: Fri, 14 Oct 2005 19:31:56 +0000 (+0300)
Subject: [PATCH] ARM: OMAP: USB peripheral DMA update'
X-Git-Tag: v2.6.15-omap2~148
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=3e709eac74dd4aab0c1220810dc41c823207145f;p=linux-2.6-omap-h63xx.git

[PATCH] ARM: OMAP: USB peripheral DMA update'

The change to make DMA work two bytes at a time omitted an important
tweak that affects the file_storage gadget:  it needs to recognize when
the host writes an odd number of bytes.  (The change was made to get
past a controller lockup that seemed to be caused by byte-at-a-time DMA
using too much bandwidth on one of the I/O busses during network stress
testing.  The network layer ignores such extra bytes.)

This patch resolves that issue by checking the relevant bit and adjusting
the rx byte count, so that for example a legal 13 byte request doesn't
morph into an illegal 14 byte one any more.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>
---

diff --git a/drivers/usb/gadget/omap_udc.c b/drivers/usb/gadget/omap_udc.c
index ff5533e6956..d1b797bff9c 100644
--- a/drivers/usb/gadget/omap_udc.c
+++ b/drivers/usb/gadget/omap_udc.c
@@ -691,7 +691,7 @@ static void next_out_dma(struct omap_ep *ep, struct omap_req *req)
 }
 
 static void
-finish_out_dma(struct omap_ep *ep, struct omap_req *req, int status)
+finish_out_dma(struct omap_ep *ep, struct omap_req *req, int status, int one)
 {
 	u16	count;
 
@@ -699,6 +699,8 @@ finish_out_dma(struct omap_ep *ep, struct omap_req *req, int status)
 		ep->dma_counter = (u16) (req->req.dma + req->req.actual);
 	count = dma_dest_len(ep, req->req.dma + req->req.actual);
 	count += req->req.actual;
+	if (one)
+		count--;
 	if (count <= req->req.length)
 		req->req.actual = count;
 
@@ -747,7 +749,7 @@ static void dma_irq(struct omap_udc *udc, u16 irq_src)
 		if (!list_empty(&ep->queue)) {
 			req = container_of(ep->queue.next,
 					struct omap_req, queue);
-			finish_out_dma(ep, req, 0);
+			finish_out_dma(ep, req, 0, dman_stat & UDC_DMA_RX_SB);
 		}
 		UDC_IRQ_SRC_REG = UDC_RXN_EOT;
 
@@ -925,7 +927,7 @@ static void dma_channel_release(struct omap_ep *ep)
 		while (UDC_RXDMA_CFG_REG & mask)
 			udelay(10);
 		if (req)
-			finish_out_dma(ep, req, -ECONNRESET);
+			finish_out_dma(ep, req, -ECONNRESET, 0);
 	}
 	omap_free_dma(ep->lch);
 	ep->dma_channel = 0;