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From: Hannu Hartikainen <>
Cc: Oliver Neukum <>, Hannu Hartikainen <>
Subject: [PATCH] USB: cdc-acm: blacklist Heimann USB Appset device
Date: Tue, 22 Jun 2021 17:14:54 +0300
Message-ID: <> (raw)

The device (32a7:0000 Heimann Sensor GmbH USB appset demo) claims to be
a CDC-ACM device in its descriptors but in fact is not. If it is run
with echo disabled it returns garbled data, probably due to something
that happens in the TTY layer. And when run with echo enabled (the
default), it will mess up the calibration data of the sensor the first
time any data is sent to the device.

In short, I had a bad time after connecting the sensor and trying to get
it to work. I hope blacklisting it in the cdc-acm driver will save
someone else a bit of trouble.

Signed-off-by: Hannu Hartikainen <>

This is my first time submitting a patch. I hope I'll be able to submit
a driver for this device later. The device is a microcontroller-based
USB implementation/converter for a thermal camera that communicates over

 drivers/usb/class/cdc-acm.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index ca7a61190dd9..d50b606d09aa 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -1959,6 +1959,11 @@ static const struct usb_device_id acm_ids[] = {
 	.driver_info = IGNORE_DEVICE,
+	/* Exclude Heimann Sensor GmbH USB appset demo */
+	{ USB_DEVICE(0x32a7, 0x0000),
+	.driver_info = IGNORE_DEVICE,
+	},
 	/* control interfaces without any protocol set */

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Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-22 14:14 Hannu Hartikainen [this message]
2021-06-22 19:54 ` Greg KH
2021-06-22 21:00   ` Hannu Hartikainen

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