From: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
commit 3232a3ce55edfc0d7f8904543b4088a5339c2b2b upstream.
The programming guide incorrectly stated that the DCFG.bInterval_m1 must
be set to 0 when operating in fullspeed. There's no such limitation for
all IPs. See DWC_usb3x programming guide section 3.2.2.1.
Fixes: a1679af85b2a ("usb: dwc3: gadget: Fix setting of DEPCFG.bInterval_m1")
Cc: <stable@xxxxxxxxxxxxxxx>
Acked-by: Felipe Balbi <balbi@xxxxxxxxxx>
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/5d4139ae89d810eb0a2d8577fb096fc88e87bfab.1618472454.git.Thinh.Nguyen@xxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/dwc3/gadget.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -608,12 +608,14 @@ static int dwc3_gadget_set_ep_config(str
u8 bInterval_m1;
/*
- * Valid range for DEPCFG.bInterval_m1 is from 0 to 13, and it
- * must be set to 0 when the controller operates in full-speed.
+ * Valid range for DEPCFG.bInterval_m1 is from 0 to 13.
+ *
+ * NOTE: The programming guide incorrectly stated bInterval_m1
+ * must be set to 0 when operating in fullspeed. Internally the
+ * controller does not have this limitation. See DWC_usb3x
+ * programming guide section 3.2.2.1.
*/
bInterval_m1 = min_t(u8, desc->bInterval - 1, 13);
- if (dwc->gadget->speed == USB_SPEED_FULL)
- bInterval_m1 = 0;
if (usb_endpoint_type(desc) == USB_ENDPOINT_XFER_INT &&
dwc->gadget->speed == USB_SPEED_FULL)
