The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3232a3ce55edfc0d7f8904543b4088a5339c2b2b Mon Sep 17 00:00:00 2001

From: Thinh Nguyen Thinh.Nguyen@synopsys.com Date: Thu, 15 Apr 2021 00:41:58 -0700 Subject: [PATCH] usb: dwc3: gadget: Remove FS bInterval_m1 limitation

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@vger.kernel.org Acked-by: Felipe Balbi balbi@kernel.org Signed-off-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Link: https://lore.kernel.org/r/5d4139ae89d810eb0a2d8577fb096fc88e87bfab.161847245... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 1a632a3faf7f..90f4f9e69b22 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -607,12 +607,14 @@ static int dwc3_gadget_set_ep_config(struct dwc3_ep *dep, unsigned int action) 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)