Messages in this thread Patch in this message | | | From | Tony Lindgren <> | Subject | [PATCH] serial: core: Fix runtime PM handling for pending tx | Date | Mon, 23 Oct 2023 10:48:54 +0300 |
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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") 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> --- drivers/tty/serial/serial_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -146,7 +146,7 @@ static void __uart_start(struct uart_state *state) /* 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; } -- 2.42.0
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