On 17/01/18 14:01, Daniel Vetter 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.jo...@linaro.org>
Cc: Daniel Thompson <daniel.thomp...@linaro.org>
Cc: Jingoo Han <jingooh...@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vet...@intel.com>
---
  drivers/video/backlight/pandora_bl.c | 26 +++++++++++++++++++-------
  1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/video/backlight/pandora_bl.c 
b/drivers/video/backlight/pandora_bl.c
index a186bc677c7d..6bd159946a47 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

Nit, but we using old_state like a bitfield so, BIT(0)?


+};
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;

Well, we were using it like a bitfield until this bit...


return 0;
  }
@@ -109,15 +113,23 @@ 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");
+               kfree(priv);

Why can't we rely on devres for cleanup?


                return PTR_ERR(bl);
        }
@@ -126,7 +138,7 @@ 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);

Reply via email to