[PATCH] usb: gadget: Do not handle OS Descriptors config separately

From: Elson Roy Serrao
Date: Mon Feb 13 2023 - 18:45:47 EST


Consider a multi-configuration composition in which the last
configuration uses OS descriptors. Since this configuration will
be sent first, the host may choose this config if it matches the
choosing criteria and ignore the user configured order of the
multi-config composition. Moreover linux based hosts do not re-order
the received configurations based on their indices but process them
in FIFO order. This may result in the host never choosing the user
desired configuration because of the re-order caused by sending the
OS descriptor config first. To avoid this, follow the user configured
order and do not handle OS descriptor config separately.

Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
---
drivers/usb/gadget/composite.c | 9 ---------
1 file changed, 9 deletions(-)

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index fa7dd6c..685003a 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -589,18 +589,9 @@ static int config_desc(struct usb_composite_dev *cdev, unsigned w_value)
w_value &= 0xff;

pos = &cdev->configs;
- c = cdev->os_desc_config;
- if (c)
- goto check_config;
-
while ((pos = pos->next) != &cdev->configs) {
c = list_entry(pos, typeof(*c), list);

- /* skip OS Descriptors config which is handled separately */
- if (c == cdev->os_desc_config)
- continue;
-
-check_config:
/* ignore configs that won't work at this speed */
switch (speed) {
case USB_SPEED_SUPER_PLUS:
--
2.7.4