Re: [PATCH v5 3/3] usb: cdc-acm: Ignore Exar XR21V141X when serial driver is built
From: Johan Hovold <johan@kernel.org>
Date: 2021-01-21 10:26:20
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On Sun, Nov 22, 2020 at 10:38:22PM +0530, Manivannan Sadhasivam wrote:
From: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> 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@kernel.org> Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
quoted hunk ↗ jump to hunk
--- 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