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| author | Jiri Slaby (SUSE) <jirislaby@kernel.org> | 2023-08-11 08:43:40 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-08-11 21:19:18 +0200 |
| commit | 3d9e6f556e235ddcdc9f73600fdd46fe1736b090 (patch) | |
| tree | 2bedab93311b45f164aaa60044b707c2593fe35d /drivers/tty | |
| parent | 3c4f8333b582487a2d1e02171f1465531cde53e3 (diff) | |
| download | lwn-3d9e6f556e235ddcdc9f73600fdd46fe1736b090.tar.gz lwn-3d9e6f556e235ddcdc9f73600fdd46fe1736b090.zip | |
serial: 8250: drop lockdep annotation from serial8250_clear_IER()
The port lock is not always held when calling serial8250_clear_IER().
When an oops is in progress, the lock is tried to be taken and when it
is not, a warning is issued:
WARNING: CPU: 0 PID: 1 at drivers/tty/serial/8250/8250_port.c:707 +0x57/0x60
Modules linked in:
CPU: 0 PID: 1 Comm: init Not tainted 6.5.0-rc5-1.g225bfb7-default+ #774 00f1be860db663ed29479b8255d3b01ab1135bd3
Hardware name: QEMU Standard PC ...
RIP: 0010:serial8250_clear_IER+0x57/0x60
...
Call Trace:
<TASK>
serial8250_console_write+0x9e/0x4b0
console_flush_all+0x217/0x5f0
...
Therefore, remove the annotation as it doesn't hold for all invocations.
The other option would be to make the lockdep test conditional on
'oops_in_progress' or pass 'locked' from serial8250_console_write(). I
don't think, that is worth it.
Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Cc: John Ogness <john.ogness@linutronix.de>
Fixes: d0b309a5d3f4 (serial: 8250: synchronize and annotate UART_IER access)
Link: https://lore.kernel.org/r/20230811064340.13400-1-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 8df5be8ca824..483bb552cdc4 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -703,9 +703,6 @@ static void serial8250_set_sleep(struct uart_8250_port *p, int sleep) static void serial8250_clear_IER(struct uart_8250_port *up) { - /* Port locked to synchronize UART_IER access against the console. */ - lockdep_assert_held_once(&up->port.lock); - if (up->capabilities & UART_CAP_UUE) serial_out(up, UART_IER, UART_IER_UUE); else |