[PATCH 3.16 059/233] usb: musb: tusb6010_omap: Do not reset the other direction's packet size

[Ben Hutchings]

3.16.48-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Ujfalusi <peter.ujfalusi@xxxxxx>

commit 6df2b42f7c040d57d9ecb67244e04e905ab87ac6 upstream.

We have one register for each EP to set the maximum packet size for both
TX and RX.
If for example an RX programming would happen before the previous TX
transfer finishes we would reset the TX packet side.

To fix this issue, only modify the TX or RX part of the register.

Fixes: 550a7375fe72 ("USB: Add MUSB and TUSB support")
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Signed-off-by: Bin Liu <b-liu@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/musb/tusb6010_omap.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

--- a/drivers/usb/musb/tusb6010_omap.c
+++ b/drivers/usb/musb/tusb6010_omap.c
@@ -220,6 +220,7 @@ static int tusb_omap_dma_program(struct
 	u32				dma_remaining;
 	int				src_burst, dst_burst;
 	u16				csr;
+	u32				psize;
 	int				ch;
 	s8				dmareq;
 	s8				sync_dev;
@@ -391,15 +392,19 @@ static int tusb_omap_dma_program(struct
 
 	if (chdat->tx) {
 		/* Send transfer_packet_sz packets at a time */
-		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
-			chdat->transfer_packet_sz);
+		psize = musb_readl(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET);
+		psize &= ~0x7ff;
+		psize |= chdat->transfer_packet_sz;
+		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET, psize);
 
 		musb_writel(ep_conf, TUSB_EP_TX_OFFSET,
 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));
 	} else {
 		/* Receive transfer_packet_sz packets at a time */
-		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET,
-			chdat->transfer_packet_sz << 16);
+		psize = musb_readl(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET);
+		psize &= ~(0x7ff << 16);
+		psize |= (chdat->transfer_packet_sz << 16);
+		musb_writel(ep_conf, TUSB_EP_MAX_PACKET_SIZE_OFFSET, psize);
 
 		musb_writel(ep_conf, TUSB_EP_RX_OFFSET,
 			TUSB_EP_CONFIG_XFR_SIZE(chdat->transfer_len));