Re: [PATCH v2 3/5] gpio: use new gpio_set_config() helper in more places

From: Guenter Roeck
Date: Sat Mar 16 2019 - 10:20:30 EST


On Sat, Mar 16, 2019 at 02:45:19PM +0100, Thomas Petazzoni wrote:
> Hello,
>
> On Fri, 15 Mar 2019 18:43:52 -0700
> Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> > > index cf8a4402fef1..9762a836fec9 100644
> > > --- a/drivers/gpio/gpiolib.c
> > > +++ b/drivers/gpio/gpiolib.c
> > > @@ -2762,7 +2762,7 @@ int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
> > > }
> > >
> > > config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
> > > - return chip->set_config(chip, gpio_chip_hwgpio(desc), config);
> > > + return gpio_set_config(chip, gpio_chip_hwgpio(desc), config);
> >
> > Are you sure this is correct ? This patch results in a number of tracebacks
> > in mainline. Reverting it fixes the problem.
> >
> > gpio_set_config() seems to pack config, but it is already packed above.
> > That seems a bit suspicious.
>
> I'll have a look. In the mean time, I'm fine with the patch being
> reverted.
>

I don't know the code well enough to make a recommendation one way or another
(meaning I am not entirely sure if the aspeed code generating the traceback code
is correct). However, the attached does fix the problem for me, suggesting that
gpio_set_config() might be missing an argument.

Guenter

---

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 144af0733581..e972836e8d8f 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2563,9 +2563,9 @@ EXPORT_SYMBOL_GPL(gpiochip_free_own_desc);
*/

static int gpio_set_config(struct gpio_chip *gc, unsigned offset,
- enum pin_config_param mode)
+ enum pin_config_param mode, u32 argument)
{
- unsigned long config = { PIN_CONF_PACKED(mode, 0) };
+ unsigned long config = { PIN_CONF_PACKED(mode, argument) };

return gc->set_config ? gc->set_config(gc, offset, config) : -ENOTSUPP;
}
@@ -2619,10 +2619,10 @@ int gpiod_direction_input(struct gpio_desc *desc)

if (test_bit(FLAG_PULL_UP, &desc->flags))
gpio_set_config(chip, gpio_chip_hwgpio(desc),
- PIN_CONFIG_BIAS_PULL_UP);
+ PIN_CONFIG_BIAS_PULL_UP, 0);
else if (test_bit(FLAG_PULL_DOWN, &desc->flags))
gpio_set_config(chip, gpio_chip_hwgpio(desc),
- PIN_CONFIG_BIAS_PULL_DOWN);
+ PIN_CONFIG_BIAS_PULL_DOWN, 0);

trace_gpio_direction(desc_to_gpio(desc), 1, status);

@@ -2727,7 +2727,7 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) {
/* First see if we can enable open drain in hardware */
ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
- PIN_CONFIG_DRIVE_OPEN_DRAIN);
+ PIN_CONFIG_DRIVE_OPEN_DRAIN, 0);
if (!ret)
goto set_output_value;
/* Emulate open drain by not actively driving the line high */
@@ -2736,7 +2736,7 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
}
else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) {
ret = gpio_set_config(gc, gpio_chip_hwgpio(desc),
- PIN_CONFIG_DRIVE_OPEN_SOURCE);
+ PIN_CONFIG_DRIVE_OPEN_SOURCE, 0);
if (!ret)
goto set_output_value;
/* Emulate open source by not actively driving the line low */
@@ -2744,7 +2744,7 @@ int gpiod_direction_output(struct gpio_desc *desc, int value)
return gpiod_direction_input(desc);
} else {
gpio_set_config(gc, gpio_chip_hwgpio(desc),
- PIN_CONFIG_DRIVE_PUSH_PULL);
+ PIN_CONFIG_DRIVE_PUSH_PULL, 0);
}

set_output_value:
@@ -2764,19 +2764,11 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output);
int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
{
struct gpio_chip *chip;
- unsigned long config;

VALIDATE_DESC(desc);
chip = desc->gdev->chip;
- if (!chip->set || !chip->set_config) {
- gpiod_dbg(desc,
- "%s: missing set() or set_config() operations\n",
- __func__);
- return -ENOTSUPP;
- }
-
- config = pinconf_to_config_packed(PIN_CONFIG_INPUT_DEBOUNCE, debounce);
- return gpio_set_config(chip, gpio_chip_hwgpio(desc), config);
+ return gpio_set_config(chip, gpio_chip_hwgpio(desc),
+ PIN_CONFIG_INPUT_DEBOUNCE, debounce);
}
EXPORT_SYMBOL_GPL(gpiod_set_debounce);

@@ -2791,7 +2783,6 @@ EXPORT_SYMBOL_GPL(gpiod_set_debounce);
int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)
{
struct gpio_chip *chip;
- unsigned long packed;
int gpio;
int rc;

@@ -2807,13 +2798,8 @@ int gpiod_set_transitory(struct gpio_desc *desc, bool transitory)

/* If the driver supports it, set the persistence state now */
chip = desc->gdev->chip;
- if (!chip->set_config)
- return 0;
-
- packed = pinconf_to_config_packed(PIN_CONFIG_PERSIST_STATE,
- !transitory);
gpio = gpio_chip_hwgpio(desc);
- rc = gpio_set_config(chip, gpio, packed);
+ rc = gpio_set_config(chip, gpio, PIN_CONFIG_PERSIST_STATE, !transitory);
if (rc == -ENOTSUPP) {
dev_dbg(&desc->gdev->dev, "Persistence not supported for GPIO %d\n",
gpio);