On Mon, Feb 13, 2023 at 03:45:25PM -0800, Elson Roy Serrao wrote:
> 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.
That is up to the host, so why is this an issue?
> Moreover linux based hosts do not re-order
> the received configurations based on their indices but process them
> in FIFO order.
s/linux/Linux/
> 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.
I do not understand, what reordering is happening, and by whom?
>
> Signed-off-by: Elson Roy Serrao <quic_eserrao@xxxxxxxxxxx>
What commit does this fix?
> ---
> 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:
This feels wrong, are you sure that this code isn't here for a reason?
How did you test this?
thanks,
greg k-h
