From 3cda7919d5cb7f7fd2c62c7de8ba4534fca6a761 Mon Sep 17 00:00:00 2001 From: William Wu Date: Fri, 22 Aug 2025 11:36:09 +0800 Subject: [PATCH] usb: gadget: configfs: Correctly set use_os_string at bind [ Upstream commit e271cc0d25015f4be6c88bd7731444644eb352c2 ] 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 Signed-off-by: Sasha Levin --- drivers/usb/gadget/configfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/usb/gadget/configfs.c b/drivers/usb/gadget/configfs.c index cdbf12639dfa7..f55dcc3a40184 100644 --- a/drivers/usb/gadget/configfs.c +++ b/drivers/usb/gadget/configfs.c @@ -1356,6 +1356,8 @@ 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]) { -- 2.47.3