linux/drivers/tty
Tony Lindgren 1ba5594739 serial: 8250: Reinit port->pm on port specific driver unbind
[ Upstream commit 04e82793f0 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-24 17:36:47 +01:00
..
hvc hvc/xen: prevent concurrent accesses to the shared ring 2023-03-30 12:47:48 +02:00
ipwireless
serdev
serial serial: 8250: Reinit port->pm on port specific driver unbind 2023-05-24 17:36:47 +01:00
vt vc_screen: modify vcs_size() handling in vcs_read() 2023-03-11 13:57:30 +01:00
amiserial.c
ehv_bytechan.c
goldfish.c tty: drivers/tty/, stop using tty_schedule_flip() 2022-07-29 17:25:31 +02:00
Kconfig
Makefile
mips_ejtag_fdc.c
moxa.c tty: drivers/tty/, stop using tty_schedule_flip() 2022-07-29 17:25:31 +02:00
moxa.h
mxser.c
n_gsm.c tty: n_gsm: fix sleep-in-atomic-context bug in gsm_control_send 2022-11-26 09:24:35 +01:00
n_hdlc.c
n_null.c
n_tty.c tty: n_tty: Restore EOF push handling behavior 2022-06-14 18:36:03 +02:00
nozomi.c
pty.c tty: use new tty_insert_flip_string_and_push_buffer() in pty_write() 2022-07-29 17:25:32 +02:00
synclink_gt.c tty: synclink_gt: Fix null-pointer-dereference in slgt_clean() 2022-06-14 18:36:20 +02:00
sysrq.c workqueue: Introduce show_one_worker_pool and show_one_workqueue. 2023-05-11 23:00:35 +09:00
tty_audit.c
tty_baudrate.c
tty_buffer.c tty: use new tty_insert_flip_string_and_push_buffer() in pty_write() 2022-07-29 17:25:32 +02:00
tty_io.c tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH 2023-05-11 23:00:16 +09:00
tty_ioctl.c tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH 2023-05-11 23:00:16 +09:00
tty_jobctrl.c
tty_ldisc.c
tty_ldsem.c
tty_mutex.c
tty_port.c
tty.h tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH 2023-05-11 23:00:16 +09:00
ttynull.c
vcc.c