Hmm, CCing TTY MAINTAINERS entry would not hurt.
On 19. 11. 25, 22:29, Łukasz Bartosik wrote:
From: Łukasz Bartosik ukaszb@chromium.org
When DbC is disconnected then xhci_dbc_tty_unregister_device() is called. However if there is any user space process blocked on write to DbC terminal device then it will never be signalled and thus stay blocked indifinitely.
indefinitely
This fix adds a tty_vhangup() call in xhci_dbc_tty_unregister_device(). The tty_vhangup() wakes up any blocked writers and causes subsequent write attempts to DbC terminal device to fail.
Cc: stable@vger.kernel.org Fixes: dfba2174dc42 ("usb: xhci: Add DbC support in xHCI driver") Signed-off-by: Łukasz Bartosik ukaszb@chromium.org
Changes in v2:
- Replaced tty_hangup() with tty_vhangup()
Why exactly?
--- a/drivers/usb/host/xhci-dbgtty.c +++ b/drivers/usb/host/xhci-dbgtty.c @@ -535,6 +535,12 @@ static void xhci_dbc_tty_unregister_device(struct xhci_dbc *dbc) if (!port->registered) return;
- /*
* Hang up the TTY. This wakes up any blocked* writers and causes subsequent writes to fail.*/- tty_vhangup(port->port.tty);
This is wrong IMO: 1) what if there is no tty currently open? Ie. tty is NULL. 2) you schedule a tty hangup work and destroy the port right after:
tty_unregister_device(dbc_tty_driver, port->minor); xhci_dbc_tty_exit_port(port); port->registered = false;
You should to elaborate how this is supposed to work?
thanks,