linux/drivers/tty
Tony Lindgren 04e82793f0 serial: 8250: Reinit port->pm on port specific driver unbind
When we unbind a serial port hardware specific 8250 driver, the generic
serial8250 driver takes over the port. After that we see an oops about 10
seconds later. This can produce the following at least on some TI SoCs:

Unhandled fault: imprecise external abort (0x1406)
Internal error: : 1406 [#1] SMP ARM

Turns out that we may still have the serial port hardware specific driver
port->pm in use, and serial8250_pm() tries to call it after the port
specific driver is gone:

serial8250_pm [8250_base] from uart_change_pm+0x54/0x8c [serial_base]
uart_change_pm [serial_base] from uart_hangup+0x154/0x198 [serial_base]
uart_hangup [serial_base] from __tty_hangup.part.0+0x328/0x37c
__tty_hangup.part.0 from disassociate_ctty+0x154/0x20c
disassociate_ctty from do_exit+0x744/0xaac
do_exit from do_group_exit+0x40/0x8c
do_group_exit from __wake_up_parent+0x0/0x1c

Let's fix the issue by calling serial8250_set_defaults() in
serial8250_unregister_port(). This will set the port back to using
the serial8250 default functions, and sets the port->pm to point to
serial8250_pm.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Link: https://lore.kernel.org/r/20230418101407.12403-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-20 13:43:41 +02:00
..
hvc xen: branch for v6.3-rc4 2023-03-24 09:44:43 -07:00
ipwireless
serdev serdev: Set fwnode for serdev devices 2023-03-09 17:09:56 +01:00
serial serial: 8250: Reinit port->pm on port specific driver unbind 2023-04-20 13:43:41 +02:00
vt tty: vt: protect KD_FONT_OP_GET_TALL from unbound access 2023-03-09 17:56:56 +01:00
amiserial.c tty: Convert hw_stopped in tty_struct to bool 2023-03-17 15:01:09 +01:00
ehv_bytechan.c tty: evh_bytechan: Replace NO_IRQ by 0 2022-11-02 08:10:42 +01:00
goldfish.c tty: goldfish: Fix free_irq() on remove 2022-06-10 13:31:31 +02:00
Kconfig tty: Fix typo in LEGACY_TIOCSTI Kconfig description 2023-04-05 19:36:00 +02:00
Makefile
mips_ejtag_fdc.c serial: Convert SERIAL_XMIT_SIZE to UART_XMIT_SIZE 2022-06-27 14:41:31 +02:00
moxa.c tty: moxa: Rename dtr/rts parameters/variables to active 2023-01-19 16:04:35 +01:00
mxser.c tty: Convert hw_stopped in tty_struct to bool 2023-03-17 15:01:09 +01:00
n_gsm.c tty: n_gsm: fix redundant assignment of gsm->encoding 2023-04-20 13:27:10 +02:00
n_hdlc.c tty: n_hdlc: remove HDLC_MAGIC 2022-09-22 16:12:34 +02:00
n_null.c
n_tty.c n_tty: Reindent if condition 2023-03-17 15:01:09 +01:00
nozomi.c
pty.c tty: Make ->set_termios() old ktermios const 2022-08-30 14:22:35 +02:00
rpmsg_tty.c
synclink_gt.c tty: synclink_gt: don't allocate and pass dummy flags 2023-04-20 13:32:53 +02:00
sysrq.c treewide: Convert del_timer*() to timer_shutdown*() 2022-12-25 13:38:09 -08:00
tty_audit.c
tty_baudrate.c tty: Fix comment style in tty_termios_input_baud_rate() 2022-08-30 14:22:34 +02:00
tty_buffer.c tty: Convert tty_buffer flags to bool 2022-11-09 13:02:16 +01:00
tty_io.c tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH 2023-03-29 10:55:53 +02:00
tty_ioctl.c tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH 2023-03-29 10:55:53 +02:00
tty_jobctrl.c signal: Replace __group_send_sig_info with send_signal_locked 2022-05-11 14:33:17 -05:00
tty_ldisc.c tty: tty_ldisc: Remove the ret variable 2023-03-09 17:11:18 +01:00
tty_ldsem.c
tty_mutex.c tty: remove TTY_MAGIC 2022-09-22 16:12:34 +02:00
tty_port.c tty: Convert ->dtr_rts() to take bool argument 2023-01-19 16:04:35 +01:00
tty.h tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH 2023-03-29 10:55:53 +02:00
ttynull.c
vcc.c termios: start unifying non-UAPI parts of asm/termios.h 2022-09-09 10:44:34 +02:00