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authorTony Lindgren <tony@atomide.com>2023-10-23 10:48:54 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-10-24 12:35:29 +0300
commit6f699743aebf07538e506a46c5965eb8bdd2c716 (patch)
treec3eaea7e09b1b62946ba990781abd574b813ffe9 /drivers/tty
parentb0eaf27f202813f28af77e33e80ec0f05a34df01 (diff)
downloadlinux-6f699743aebf07538e506a46c5965eb8bdd2c716.tar.xz
serial: core: Fix runtime PM handling for pending tx
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>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/serial_core.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index b106eb3943d0..f1348a509552 100644
--- 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;
}