On Sun, Nov 22, 2020 at 10:38:22PM +0530, Manivannan Sadhasivam wrote:
> From: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
>
> The RTS/CTS line discipline for this device doesn't follow
> the standard. So, in order to properly support TX, a separate
> driver is needed.
This took a bit of effort to understand, but I think I know what you're
referring to now. In ACM mode the device has RTS/CTS flow control
enabled, which means TX will be disabled in case CTS isn't wired up
correctly.
It as nothing to do with line disciplines though.
> Ensure that cdc_acm will ignore it during probe time, if the
> Kernel is built with support for it.
>
> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> Signed-off-by: Manivannan Sadhasivam <mani@xxxxxxxxxx>
> ---
> drivers/usb/class/cdc-acm.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
> index 30ef946a8e1a..719829e6b6db 100644
> --- a/drivers/usb/class/cdc-acm.c
> +++ b/drivers/usb/class/cdc-acm.c
> @@ -1890,6 +1890,12 @@ static const struct usb_device_id acm_ids[] = {
> },
> #endif
>
> +#if IS_ENABLED(CONFIG_USB_SERIAL_XR)
> + { USB_DEVICE(0x04e2, 0x1410), /* Ignore XR21V141X USB to Serial converter */
> + .driver_info = IGNORE_DEVICE,
> + },
> +#endif
> +
> /*Samsung phone in firmware update mode */
> { USB_DEVICE(0x04e8, 0x685d),
> .driver_info = IGNORE_DEVICE,
I've rewritten the commit message and applied this one now.
Johan
