From cf9f7a6ee7b1f53f9ae13da55585b7d16aee2460 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Mon, 28 Aug 2023 17:43:03 +0200 Subject: usb: raw-gadget: return USB_GADGET_DELAYED_STATUS from setup() Return USB_GADGET_DELAYED_STATUS from the setup() callback for 0-length transfers as a workaround to stop some UDC drivers (e.g. dwc3) from automatically proceeding with the status stage. This workaround should be removed once all UDC drivers are fixed to always delay the status stage until a response is queued to EP0. Signed-off-by: Andrey Konovalov Link: https://lore.kernel.org/r/c56077322f0d3fc6d504092a266cb89d75701087.1693237258.git.andreyknvl@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/legacy/raw_gadget.c | 11 +++++++++++ 1 file changed, 11 insertions(+) (limited to 'drivers/usb') diff --git a/drivers/usb/gadget/legacy/raw_gadget.c b/drivers/usb/gadget/legacy/raw_gadget.c index e549022642e5..b9ecc55a2ce2 100644 --- a/drivers/usb/gadget/legacy/raw_gadget.c +++ b/drivers/usb/gadget/legacy/raw_gadget.c @@ -25,6 +25,7 @@ #include #include #include +#include #include @@ -363,6 +364,16 @@ static int gadget_setup(struct usb_gadget *gadget, out_unlock: spin_unlock_irqrestore(&dev->lock, flags); out: + if (ret == 0 && ctrl->wLength == 0) { + /* + * Return USB_GADGET_DELAYED_STATUS as a workaround to stop + * some UDC drivers (e.g. dwc3) from automatically proceeding + * with the status stage for 0-length transfers. + * Should be removed once all UDC drivers are fixed to always + * delay the status stage until a response is queued to EP0. + */ + return USB_GADGET_DELAYED_STATUS; + } return ret; } -- cgit v1.2.3