diff options
| author | Tony Lindgren <tony@atomide.com> | 2023-10-23 10:48:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-08 14:09:07 +0100 |
| commit | 575d3966a7da3bdab7a0edc42998453203346cbd (patch) | |
| tree | 106c8d26755d50ae50e86a572ae747a07fc71638 | |
| parent | 9f625a9ec6adf264ad5ff348f8c1c49832d8121b (diff) | |
serial: core: Fix runtime PM handling for pending tx
commit 6f699743aebf07538e506a46c5965eb8bdd2c716 upstream.
Richard reported that a serial port may end up sometimes with tx data
pending in the buffer for long periods of time.
Turns out we bail out early on any errors from pm_runtime_get(),
including -EINPROGRESS. To fix the issue, we need to ignore -EINPROGRESS
as we only care about the runtime PM usage count at this point. We check
for an active runtime PM state later on for tx.
Fixes: 84a9582fd203 ("serial: core: Start managing serial controllers to enable runtime PM")
Cc: stable <stable@kernel.org>
Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Cc: Bruce Ashfield <bruce.ashfield@gmail.com>
Cc: Mikko Rapeli <mikko.rapeli@linaro.org>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Randy MacLeod <randy.macleod@windriver.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Link: https://lore.kernel.org/r/20231023074856.61896-1-tony@atomide.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 83c419ac78bc..0c6c633c0924 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -147,7 +147,7 @@ static void __uart_start(struct tty_struct *tty) /* Increment the runtime PM usage count for the active check below */ err = pm_runtime_get(&port_dev->dev); - if (err < 0) { + if (err < 0 && err != -EINPROGRESS) { pm_runtime_put_noidle(&port_dev->dev); return; } |