This is a note to let you know that I've just added the patch titled usb: cdc-acm: Add DISABLE_ECHO for Renesas USB Download mode to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: usb-cdc-acm-add-disable_echo-for-renesas-usb-download-mode.patch and it can be found in the queue-4.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 6d853c9e4104b4fc8d55dc9cd3b99712aa347174 Mon Sep 17 00:00:00 2001 From: Chris Brandt <chris.brandt@xxxxxxxxxxx> Date: Wed, 11 Nov 2020 08:12:09 -0500 Subject: usb: cdc-acm: Add DISABLE_ECHO for Renesas USB Download mode From: Chris Brandt <chris.brandt@xxxxxxxxxxx> commit 6d853c9e4104b4fc8d55dc9cd3b99712aa347174 upstream. Renesas R-Car and RZ/G SoCs have a firmware download mode over USB. However, on reset a banner string is transmitted out which is not expected to be echoed back and will corrupt the protocol. Cc: stable <stable@xxxxxxxxxxxxxxx> Acked-by: Oliver Neukum <oneukum@xxxxxxxx> Signed-off-by: Chris Brandt <chris.brandt@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20201111131209.3977903-1-chris.brandt@xxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/class/cdc-acm.c | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1751,6 +1751,15 @@ static const struct usb_device_id acm_id { USB_DEVICE(0x0870, 0x0001), /* Metricom GS Modem */ .driver_info = NO_UNION_NORMAL, /* has no union descriptor */ }, + { USB_DEVICE(0x045b, 0x023c), /* Renesas USB Download mode */ + .driver_info = DISABLE_ECHO, /* Don't echo banner */ + }, + { USB_DEVICE(0x045b, 0x0248), /* Renesas USB Download mode */ + .driver_info = DISABLE_ECHO, /* Don't echo banner */ + }, + { USB_DEVICE(0x045b, 0x024D), /* Renesas USB Download mode */ + .driver_info = DISABLE_ECHO, /* Don't echo banner */ + }, { USB_DEVICE(0x0e8d, 0x0003), /* FIREFLY, MediaTek Inc; andrey.arapov@xxxxxxxxx */ .driver_info = NO_UNION_NORMAL, /* has no union descriptor */ }, Patches currently in stable-queue which might be from chris.brandt@xxxxxxxxxxx are queue-4.14/usb-cdc-acm-add-disable_echo-for-renesas-usb-download-mode.patch