commit d2e9a13a388304bc2a7b25a6c34c6e2ab1540a5d
author Chanho Park <chanho61.park@samsung.com> Fri Aug 31 16:54:07 2012 +0900
committer Felipe Balbi <balbi@ti.com> Fri Aug 31 12:31:40 2012 +0300
tree aedb63453beb03b021b1640de822c4c7e6932bb5
parent 2a540edf7bb02f3e968d1ce7cb355e740ba7de13

usb: dwc3: set up burst size only superspeed mode

When connection is established non-ss mode, endpoint.maxburst is correctly set
to 0, this means that current code will set maxburst bitfield on DEPCFG's
parameter 0 to the highest possible value (0x0f) which is wrong.

Even though this hasn't caused any issues so far (HW seems to ignore that when
not running in SS mode) we want to make sure maxburst bitfield is only set to
anything other than zero if we're running on SuperSpeed mode. In order to
achieve that, let's check for gadget's operating speed before setting maxburst
bitfield when issuing DEPCFG command.

[ balbi@ti.com : improved commit log a bit in order to clarify the situation ]

Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/gadget.c

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 029cf06..ba444e7 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -439,8 +439,14 @@
 	memset(&params, 0x00, sizeof(params));
 
 	params.param0 = DWC3_DEPCFG_EP_TYPE(usb_endpoint_type(desc))
-		| DWC3_DEPCFG_MAX_PACKET_SIZE(usb_endpoint_maxp(desc))
-		| DWC3_DEPCFG_BURST_SIZE(dep->endpoint.maxburst - 1);
+		| DWC3_DEPCFG_MAX_PACKET_SIZE(usb_endpoint_maxp(desc));
+
+	/* Burst size is only needed in SuperSpeed mode */
+	if (dwc->gadget.speed == USB_SPEED_SUPER) {
+		u32 burst = dep->endpoint.maxburst - 1;
+
+		params.param0 |= DWC3_DEPCFG_BURST_SIZE(burst);
+	}
 
 	if (ignore)
 		params.param0 |= DWC3_DEPCFG_IGN_SEQ_NUM;