On Wed, 25 Apr 2018, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote:
> Leaking driver internal tracking into the already massively confusing
> backlight power tracking is really confusing.
>
> Stop that by allocating a tiny driver private data structure instead.
>
> Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> Cc: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> Cc: Jingoo Han <jingoohan1@xxxxxxxxx>
> Acked-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
> Signed-off-by: Daniel Vetter <daniel.vetter@xxxxxxxxx>
Reviewed-by: Jani Nikula <jani.nikula@xxxxxxxxx>
> ---
> v2:
> - Consistently treating PANDORA_WAS_OFF as a non-bitfield
> - Drop the kfree that I left behind after switching to devm_kmalloc
> ---
> drivers/video/backlight/pandora_bl.c | 25 ++++++++++++++++++-------
> 1 file changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/video/backlight/pandora_bl.c b/drivers/video/backlight/pandora_bl.c
> index a186bc677c7d..9618766e3866 100644
> --- a/drivers/video/backlight/pandora_bl.c
> +++ b/drivers/video/backlight/pandora_bl.c
> @@ -35,11 +35,15 @@
> #define MAX_VALUE 63
> #define MAX_USER_VALUE (MAX_VALUE - MIN_VALUE)
>
> -#define PANDORABL_WAS_OFF BL_CORE_DRIVER1
> +struct pandora_private {
> + unsigned old_state;
> +#define PANDORABL_WAS_OFF 1
> +};
>
> static int pandora_backlight_update_status(struct backlight_device *bl)
> {
> int brightness = bl->props.brightness;
> + struct pandora_private *priv = bl_get_data(bl);
> u8 r;
>
> if (bl->props.power != FB_BLANK_UNBLANK)
> @@ -53,7 +57,7 @@ static int pandora_backlight_update_status(struct backlight_device *bl)
> brightness = MAX_USER_VALUE;
>
> if (brightness == 0) {
> - if (bl->props.state & PANDORABL_WAS_OFF)
> + if (priv->old_state == PANDORABL_WAS_OFF)
> goto done;
>
> /* first disable PWM0 output, then clock */
> @@ -66,7 +70,7 @@ static int pandora_backlight_update_status(struct backlight_device *bl)
> goto done;
> }
>
> - if (bl->props.state & PANDORABL_WAS_OFF) {
> + if (priv->old_state == PANDORABL_WAS_OFF) {
> /*
> * set PWM duty cycle to max. TPS61161 seems to use this
> * to calibrate it's PWM sensitivity when it starts.
> @@ -93,9 +97,9 @@ static int pandora_backlight_update_status(struct backlight_device *bl)
>
> done:
> if (brightness != 0)
> - bl->props.state &= ~PANDORABL_WAS_OFF;
> + priv->old_state = 0;
> else
> - bl->props.state |= PANDORABL_WAS_OFF;
> + priv->old_state = PANDORABL_WAS_OFF;
>
> return 0;
> }
> @@ -109,13 +113,20 @@ static int pandora_backlight_probe(struct platform_device *pdev)
> {
> struct backlight_properties props;
> struct backlight_device *bl;
> + struct pandora_private *priv;
> u8 r;
>
> + priv = devm_kmalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
> + if (!priv) {
> + dev_err(&pdev->dev, "failed to allocate driver private data\n");
> + return -ENOMEM;
> + }
> +
> memset(&props, 0, sizeof(props));
> props.max_brightness = MAX_USER_VALUE;
> props.type = BACKLIGHT_RAW;
> bl = devm_backlight_device_register(&pdev->dev, pdev->name, &pdev->dev,
> - NULL, &pandora_backlight_ops, &props);
> + priv, &pandora_backlight_ops, &props);
> if (IS_ERR(bl)) {
> dev_err(&pdev->dev, "failed to register backlight\n");
> return PTR_ERR(bl);
> @@ -126,7 +137,7 @@ static int pandora_backlight_probe(struct platform_device *pdev)
> /* 64 cycle period, ON position 0 */
> twl_i2c_write_u8(TWL_MODULE_PWM, 0x80, TWL_PWM0_ON);
>
> - bl->props.state |= PANDORABL_WAS_OFF;
> + priv->old_state = PANDORABL_WAS_OFF;
> bl->props.brightness = MAX_USER_VALUE;
> backlight_update_status(bl);
--
Jani Nikula, Intel Open Source Technology Center
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