Re: [PATCH v4 3/3] gpiolib: Show correct direction from the beginning

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On 10/2/2018 8:08 AM, Ricardo Ribalda Delgado wrote:
Current code assumes that the direction is input if direction_input
function is set.
This might not be the case on GPIOs with programmable direction.

Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@xxxxxxxxx>

I'll try to get this series tested on QDF2400 by the end of the week.

---
Changelog v4:

timur@xxxxxxxxxx:
Remove REVISIT comment

  drivers/gpio/gpiolib.c | 27 +++++++++++++--------------
  1 file changed, 13 insertions(+), 14 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6925196136ce..cad859fece65 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1344,20 +1344,6 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
spin_unlock_irqrestore(&gpio_lock, flags); - for (i = 0; i < chip->ngpio; i++) {
-		struct gpio_desc *desc = &gdev->descs[i];
-
-		desc->gdev = gdev;
-
-		/* REVISIT: most hardware initializes GPIOs as inputs (often
-		 * with pullups enabled) so power usage is minimized. Linux
-		 * code should set the gpio direction first thing; but until
-		 * it does, and in case chip->get_direction is not set, we may
-		 * expose the wrong direction in sysfs.
-		 */
-		desc->flags = !chip->direction_input ? (1 << FLAG_IS_OUT) : 0;
-	}
-
  #ifdef CONFIG_PINCTRL
  	INIT_LIST_HEAD(&gdev->pin_ranges);
  #endif
@@ -1374,6 +1360,19 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
  	if (status)
  		goto err_remove_irqchip_mask;
+ for (i = 0; i < chip->ngpio; i++) {
+		struct gpio_desc *desc = &gdev->descs[i];
+
+		desc->gdev = gdev;
+
+		if (chip->get_direction && gpiochip_line_is_valid(chip, i))
+			desc->flags = !chip->get_direction(chip, i) ?
+					(1 << FLAG_IS_OUT) : 0;
+		else
+			desc->flags = !chip->direction_input ?
+					(1 << FLAG_IS_OUT) : 0;
+	}
+
  	status = gpiochip_add_irqchip(chip, lock_key, request_key);
  	if (status)
  		goto err_remove_chip;



--
Jeffrey Hugo
Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the
Code Aurora Forum, a Linux Foundation Collaborative Project.



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