pon., 21 paź 2019 o 12:45 Daniel Thompson [off-list ref]
napisał(a):

On Sat, Oct 19, 2019 at 10:35:50AM +0200, Bartosz Golaszewski wrote:

quoted

From: Bartosz Golaszewski <redacted>

The GPIO backlight driver currently requests the line 'as is', without
acively setting its direction. This can lead to problems: if the line
is in input mode by default, we won't be able to drive it later when
updating the status and also reading its initial value doesn't make
sense for backlight setting.

Request the line 'as is' initially, so that we can read its value
without affecting it but then change the direction to output explicitly
when setting the initial brightness.

Also: check the current direction and only read the value if it's output.

Signed-off-by: Bartosz Golaszewski <redacted>

Intent looks good to me but...

quoted

---
 drivers/video/backlight/gpio_backlight.c | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c
index 3955b513f2f8..a36ac3a45b81 100644
--- a/drivers/video/backlight/gpio_backlight.c
+++ b/drivers/video/backlight/gpio_backlight.c

@@ -25,9 +25,8 @@ struct gpio_backlight {
      int def_value;
 };

-static int gpio_backlight_update_status(struct backlight_device *bl)
+static int gpio_backlight_get_curr_brightness(struct backlight_device *bl)

This function does not get the current brightness (e.g. what the
hardware is currently doing). Given we've just nuked the function that
*did* get the current brightness from the hardware this isn't an
acceptable name.

Would like something like calc_brightness() or get_next_brightness().

Fair enough, the latter sounds good in this case.

Bart