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@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 1adf6fee58ca25fb6720b8d34c919dcf5425cc9c Mon Sep 17 00:00:00 2001
From: Daniel Starke <daniel.starke@xxxxxxxxxxx>
Date: Thu, 14 Apr 2022 02:42:19 -0700
Subject: [PATCH] tty: n_gsm: fix missing tty wakeup in convergence layer type
2
gsm_control_modem() informs the virtual tty that more data can be written
after receiving a control signal octet via modem status command (MSC).
However, gsm_dlci_data() fails to do the same after receiving a control
signal octet from the convergence layer type 2 header.
Add tty_wakeup() in gsm_dlci_data() for convergence layer type 2 to fix
this.
Fixes: e1eaea46bb40 ("tty: n_gsm line discipline")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Daniel Starke <daniel.starke@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20220414094225.4527-14-daniel.starke@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 23418ee93156..f3fb66be8513 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1615,6 +1615,7 @@ static void gsm_dlci_data(struct gsm_dlci *dlci, const u8 *data, int clen)
tty = tty_port_tty_get(port);
if (tty) {
gsm_process_modem(tty, dlci, modem, slen);
+ tty_wakeup(tty);
tty_kref_put(tty);
}
fallthrough;
