diff options
| author | Bartosz Golaszewski <bartosz.golaszewski@linaro.org> | 2024-02-20 12:34:10 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-03-02 22:04:12 +0100 |
| commit | 4e489a6e93e85726a41f85d1aaaab6f603ec2d33 (patch) | |
| tree | 26fb405085b1e140a554a19fcad7a16ca11b8a09 /drivers/tty | |
| parent | b8a4ed3405d5f3f92a211ccc2579e54345bc3aeb (diff) | |
| download | linux-4e489a6e93e85726a41f85d1aaaab6f603ec2d33.tar.gz | |
serial: st-asc: don't get/put GPIOs in atomic context
Since commit 1f2bcb8c8ccd ("gpio: protect the descriptor label with
SRCU") gpiod_set_consumer_name() calls synchronize_srcu() which led to
a "sleeping in atomic context" smatch warning.
This function (along with gpiod_get/put() and all other GPIO APIs apart
from gpiod_get/set_value() and gpiod_direction_input/output()) should
have never been called with a spinlock taken. We're only fixing this now
as GPIOLIB has been rebuilt to use SRCU for access serialization which
uncovered this problem.
Move the calls to gpiod_get/put() outside the spinlock critical section.
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-gpio/deee1438-efc1-47c4-8d80-0ab2cf01d60a@moroto.mountain/
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>
Link: https://lore.kernel.org/r/20240220113410.16613-1-brgl@bgdev.pl
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/st-asc.c | 40 |
1 files changed, 24 insertions, 16 deletions
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c index bbb5595d7e24c..a23e595518488 100644 --- a/drivers/tty/serial/st-asc.c +++ b/drivers/tty/serial/st-asc.c @@ -465,6 +465,7 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios, const struct ktermios *old) { struct asc_port *ascport = to_asc_port(port); + bool manual_rts, toggle_rts = false; struct gpio_desc *gpiod; unsigned int baud; u32 ctrl_val; @@ -518,25 +519,13 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios, /* If flow-control selected, stop handling RTS manually */ if (ascport->rts) { - devm_gpiod_put(port->dev, ascport->rts); - ascport->rts = NULL; - - pinctrl_select_state(ascport->pinctrl, - ascport->states[DEFAULT]); + toggle_rts = true; + manual_rts = false; } } else { /* If flow-control disabled, it's safe to handle RTS manually */ - if (!ascport->rts && ascport->states[NO_HW_FLOWCTRL]) { - pinctrl_select_state(ascport->pinctrl, - ascport->states[NO_HW_FLOWCTRL]); - - gpiod = devm_gpiod_get(port->dev, "rts", GPIOD_OUT_LOW); - if (!IS_ERR(gpiod)) { - gpiod_set_consumer_name(gpiod, - port->dev->of_node->name); - ascport->rts = gpiod; - } - } + if (!ascport->rts && ascport->states[NO_HW_FLOWCTRL]) + manual_rts = toggle_rts = true; } if ((baud < 19200) && !ascport->force_m1) { @@ -595,6 +584,25 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios, asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN)); uart_port_unlock_irqrestore(port, flags); + + if (toggle_rts) { + if (manual_rts) { + pinctrl_select_state(ascport->pinctrl, + ascport->states[NO_HW_FLOWCTRL]); + + gpiod = devm_gpiod_get(port->dev, "rts", GPIOD_OUT_LOW); + if (!IS_ERR(gpiod)) { + gpiod_set_consumer_name(gpiod, + port->dev->of_node->name); + ascport->rts = gpiod; + } + } else { + devm_gpiod_put(port->dev, ascport->rts); + ascport->rts = NULL; + pinctrl_select_state(ascport->pinctrl, + ascport->states[DEFAULT]); + } + } } static const char *asc_type(struct uart_port *port) |