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| author | Tony Lindgren <tony@atomide.com> | 2023-10-23 10:48:54 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-11-08 11:56:24 +0100 |
| commit | f1125301091a2bbdca0562fdc70a2482c8fcca24 (patch) | |
| tree | be67b3f03c10eba80a271625f29ec183c644b7c0 | |
| parent | be3e3ab567b77fbf49e61fc7cea2fff84540de97 (diff) | |
| download | linux-stable-f1125301091a2bbdca0562fdc70a2482c8fcca24.tar.gz linux-stable-f1125301091a2bbdca0562fdc70a2482c8fcca24.tar.bz2 linux-stable-f1125301091a2bbdca0562fdc70a2482c8fcca24.zip | |
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 d5ba6e90bd95..f912f8bf1e63 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; } |