The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 64690a90cd7c6db16d3af8616be1f4bf8d492850 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025081847-resident-transform-fcca@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 64690a90cd7c6db16d3af8616be1f4bf8d492850 Mon Sep 17 00:00:00 2001 From: Oliver Neukum oneukum@suse.com Date: Thu, 17 Jul 2025 16:12:50 +0200 Subject: [PATCH] cdc-acm: fix race between initial clearing halt and open

On the devices that need their endpoints to get an initial clear_halt, this needs to be done before the devices can be opened. That means it needs to be before the devices are registered.

Fixes: 15bf722e6f6c0 ("cdc-acm: Add support of ATOL FPrint fiscal printers") Cc: stable stable@kernel.org Signed-off-by: Oliver Neukum oneukum@suse.com Link: https://lore.kernel.org/r/20250717141259.2345605-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index c2ecfa3c8349..5a334e370f4d 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -1520,6 +1520,12 @@ static int acm_probe(struct usb_interface *intf, goto err_remove_files; }

+ if (quirks & CLEAR_HALT_CONDITIONS) { + /* errors intentionally ignored */ + usb_clear_halt(usb_dev, acm->in); + usb_clear_halt(usb_dev, acm->out); + } + tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor, &control_interface->dev); if (IS_ERR(tty_dev)) { @@ -1527,11 +1533,6 @@ static int acm_probe(struct usb_interface *intf, goto err_release_data_interface; }

- if (quirks & CLEAR_HALT_CONDITIONS) { - usb_clear_halt(usb_dev, acm->in); - usb_clear_halt(usb_dev, acm->out); - } - dev_info(&intf->dev, "ttyACM%d: USB ACM device\n", minor);

return 0;