[PATCH] net: phy: mdio-gpio: fix access that may sleep

Martin Schiller
2018-11-14T06:25:51Z

This commit re-enables support for slow GPIO pins. It was initially
introduced by commit
2d6c9091ab7630dfcf34417c6683ce4764d7d40a
and got lost by commit
7e5fbd1e0700f1bdb94508f84ec2aeb01eed7b12

Also add a warning about slow GPIO pins like it is done in i2c-gpio.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
---
drivers/net/phy/mdio-gpio.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/mdio-gpio.c b/drivers/net/phy/mdio-gpio.c
index 33265747bf39..d4430631ca6a 100644
--- a/drivers/net/phy/mdio-gpio.c
+++ b/drivers/net/phy/mdio-gpio.c
@@ -63,7 +63,7 @@ static void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
* assume the pin serves as pull-up. If direction is
* output, the default value is high.
*/
- gpiod_set_value(bitbang->mdo, 1);
+ gpiod_set_value_cansleep(bitbang->mdo, 1);
return;
}

@@ -78,7 +78,7 @@ static int mdio_get(struct mdiobb_ctrl *ctrl)
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);

- return gpiod_get_value(bitbang->mdio);
+ return gpiod_get_value_cansleep(bitbang->mdio);
}

static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
@@ -87,9 +87,9 @@ static void mdio_set(struct mdiobb_ctrl *ctrl, int what)
container_of(ctrl, struct mdio_gpio_info, ctrl);

if (bitbang->mdo)
- gpiod_set_value(bitbang->mdo, what);
+ gpiod_set_value_cansleep(bitbang->mdo, what);
else
- gpiod_set_value(bitbang->mdio, what);
+ gpiod_set_value_cansleep(bitbang->mdio, what);
}

static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
@@ -97,7 +97,7 @@ static void mdc_set(struct mdiobb_ctrl *ctrl, int what)
struct mdio_gpio_info *bitbang =
container_of(ctrl, struct mdio_gpio_info, ctrl);

- gpiod_set_value(bitbang->mdc, what);
+ gpiod_set_value_cansleep(bitbang->mdc, what);
}

static const struct mdiobb_ops mdio_gpio_ops = {
@@ -162,6 +162,11 @@ static int mdio_gpio_probe(struct platform_device *pdev)
if (ret)
return ret;

+ if (gpiod_cansleep(bitbang->mdc) || gpiod_cansleep(bitbang->mdio)
+ || gpiod_cansleep(bitbang->mdo))
+ dev_warn(&pdev->dev, "Slow GPIO pins might wreak havoc into"
+ "I2C/SMBus bus timing");
+
if (pdev->dev.of_node) {
bus_id = of_alias_get_id(pdev->dev.of_node, "mdio-gpio");
if (bus_id < 0) {
--
2.11.0