From: William Wu Date: Fri, 22 Aug 2025 03:36:09 +0000 (+0800) Subject: usb: gadget: configfs: Correctly set use_os_string at bind X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e271cc0d25015f4be6c88bd7731444644eb352c2;p=users%2Fhch%2Fmisc.git usb: gadget: configfs: Correctly set use_os_string at bind Once the use_os_string flag is set to true for some functions (e.g. adb/mtp) which need to response the OS string, and then if we re-bind the ConfigFS gadget to use the other functions (e.g. hid) which should not to response the OS string, however, because the use_os_string flag is still true, so the usb gadget response the OS string descriptor incorrectly, this can cause the USB device to be unrecognizable on the Windows system. An example of this as follows: echo 1 > os_desc/use ln -s functions/ffs.adb configs/b.1/function0 start adbd echo "" > UDC #succeed stop adbd rm configs/b.1/function0 echo 0 > os_desc/use ln -s functions/hid.gs0 configs/b.1/function0 echo "" > UDC #fail to connect on Windows This patch sets the use_os_string flag to false at bind if the functions not support OS Descriptors. Signed-off-by: William Wu Fixes: 87213d388e92 ("usb: gadget: configfs: OS String support") Link: https://lore.kernel.org/r/1755833769-25434-1-git-send-email-william.wu@rock-chips.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c index f94ea196ce54..6bcac85c5550 100644 --- a/drivers/usb/gadget/configfs.c +++ b/drivers/usb/gadget/configfs.c @@ -1750,6 +1750,8 @@ static int configfs_composite_bind(struct usb_gadget *gadget, cdev->use_os_string = true; cdev->b_vendor_code = gi->b_vendor_code; memcpy(cdev->qw_sign, gi->qw_sign, OS_STRING_QW_SIGN_LEN); + } else { + cdev->use_os_string = false; } if (gadget_is_otg(gadget) && !otg_desc[0]) {