FAILED: patch "[PATCH] Bluetooth: rfcomm: fix modem control handling" failed to apply to 6.1-stable tree
Subsystems (2)
[email protected]
maintainerThe patch below does not apply to the 6.1-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 <[email protected]>.
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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 91d35ec9b3956d6b3cf789c1593467e58855b03a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2025110242-armory-enlisted-e259@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 91d35ec9b3956d6b3cf789c1593467e58855b03a Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Thu, 23 Oct 2025 14:05:30 +0200
Subject: [PATCH] Bluetooth: rfcomm: fix modem control handling
The RFCOMM driver confuses the local and remote modem control signals, which specifically means that the reported DTR and RTS state will instead reflect the remote end (i.e. DSR and CTS).
This issue dates back to the original driver (and a follow-on update) merged in 2002, which resulted in a non-standard implementation of TIOCMSET that allowed controlling also the TS07.10 IC and DV signals by mapping them to the RI and DCD input flags, while TIOCMGET failed to return the actual state of DTR and RTS.
Note that the bogus control of input signals in tiocmset() is just dead code as those flags will have been masked out by the tty layer since 2003.
net/bluetooth/rfcomm/tty.c +11 -15
@@ -643,8 +643,8 @@ static void rfcomm_dev_modem_status(struct rfcomm_dlc *dlc, u8 v24_sig)tty_port_tty_hangup (&dev->port, true); dev->modem_status = - ((v24_sig &RFCOMM_V24_RTC ) ? (TIOCM_DSR |TIOCM_DTR ) :0 ) | - ((v24_sig &RFCOMM_V24_RTR ) ? (TIOCM_RTS |TIOCM_CTS ) :0 ) | + ((v24_sig &RFCOMM_V24_RTC ) ?TIOCM_DSR :0 ) | + ((v24_sig &RFCOMM_V24_RTR ) ?TIOCM_CTS :0 ) | ((v24_sig &RFCOMM_V24_IC ) ?TIOCM_RI :0 ) | ((v24_sig &RFCOMM_V24_DV ) ?TIOCM_CD :0 ); }
@@ -1055,10 +1055,14 @@ static void rfcomm_tty_hangup(struct tty_struct *tty)static int rfcomm_tty_tiocmget (struct tty_struct *tty) {struct rfcomm_dev *dev = tty->driver_data; +struct rfcomm_dlc *dlc = dev->dlc; +u8 v24_sig;BT_DBG ("tty %p dev %p" , tty, dev); -return dev->modem_status; +rfcomm_dlc_get_modem_status (dlc, &v24_sig); + +return (v24_sig & (TIOCM_DTR |TIOCM_RTS )) | dev->modem_status; }static int rfcomm_tty_tiocmset (struct tty_struct *tty,unsigned int set,unsigned int clear)
@@ -1071,23 +1075,15 @@ static int rfcomm_tty_tiocmset(struct tty_struct *tty, unsigned int set, unsignerfcomm_dlc_get_modem_status (dlc, &v24_sig); -if (set &TIOCM_DSR || set &TIOCM_DTR ) +if (set &TIOCM_DTR ) v24_sig |=RFCOMM_V24_RTC ; -if (set &TIOCM_RTS || set &TIOCM_CTS ) +if (set &TIOCM_RTS ) v24_sig |=RFCOMM_V24_RTR ; -if (set &TIOCM_RI ) - v24_sig |=RFCOMM_V24_IC ; -if (set &TIOCM_CD ) - v24_sig |=RFCOMM_V24_DV ; -if (clear &TIOCM_DSR || clear &TIOCM_DTR ) +if (clear &TIOCM_DTR ) v24_sig &= ~RFCOMM_V24_RTC ; -if (clear &TIOCM_RTS || clear &TIOCM_CTS ) +if (clear &TIOCM_RTS ) v24_sig &= ~RFCOMM_V24_RTR ; -if (clear &TIOCM_RI ) - v24_sig &= ~RFCOMM_V24_IC ; -if (clear &TIOCM_CD ) - v24_sig &= ~RFCOMM_V24_DV ;rfcomm_dlc_set_modem_status (dlc, v24_sig);