[PATCH 2/2] backlight: Fix blanking for L4F00242T03 LCD

[marek.vasut@gmail.com (Marek Vasut)]

Dne So 5. ?ervna 2010 11:22:02 Alberto Panizzo napsal(a):
> On sab, 2010-06-05 at 03:25 +0200, Marek Vasut wrote:
> > Dne P? 4. ?ervna 2010 09:29:43 Alberto Panizzo napsal(a):
> > > On ven, 2010-06-04 at 07:52 +0200, Marek Vasut wrote:
> > > > The LCD was turned on if the variable power was > 0, but that was
> > > > incorrect. The LCD has to be turned on in every case but POWERDOWN.
> > > > 
> > > > Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
> > > 
> > > Ack
> > > 
> > > > ---
> > > > 
> > > >  drivers/video/backlight/l4f00242t03.c |    2 +-
> > > >  1 files changed, 1 insertions(+), 1 deletions(-)
> > > > 
> > > > diff --git a/drivers/video/backlight/l4f00242t03.c
> > > > b/drivers/video/backlight/l4f00242t03.c index 9093ef0..ac20b2e 100644
> > > > --- a/drivers/video/backlight/l4f00242t03.c
> > > > +++ b/drivers/video/backlight/l4f00242t03.c
> > > > @@ -78,7 +78,7 @@ static int l4f00242t03_lcd_power_set(struct
> > > > lcd_device *ld, int power)
> > > > 
> > > >  	const u16 slpin = 0x10;
> > > >  	const u16 disoff = 0x28;
> > > > 
> > > > -	if (power) {
> > > > +	if (power < FB_BLANK_POWERDOWN) {
> > > > 
> > > >  		if (priv->lcd_on)
> > > >  		
> > > >  			return 0;
> > > 
> > > lcd.h states:
> > > struct lcd_ops {
> > > 
> > > 	/* Get the LCD panel power status (0: full on, 1..3: controller
> > > 	
> > > 	   power on, flat panel power off, 4: full off), see FB_BLANK_XXX */
> > > 	
> > > 	int (*get_power)(struct lcd_device *);
> > > 	/* Enable or disable power to the LCD (0: on; 4: off, see
> > > 	FB_BLANK_XXX)
> > 
> > */
> > 
> > > 	int (*set_power)(struct lcd_device *, int power);
> > > 
> > > AFAIK the gray area between FB_BLANK_NORMAL and FB_BLANK_HSYNC_SUSPEND
> > > can be chosen as needs.
> > > 
> > > Why not:
> > > 
> > > + #define POWER_IS_ON(pwr)	((pwr) <= FB_BLANK_NORMAL)
> > > 
> > > ...
> > > 
> > > -	if (power) {
> > > +	if (POWER_IS_ON(power)) {
> > > 
> > >  		if (priv->lcd_on)
> > >  		
> > >  			return 0;
> > > 
> > > So with FB_BLANK_NORMAL the lcd is active and on -> low latencies
> > > in re-enabling the video out, but for !POWER_IS_ON(power) we will send
> > > the lcd to standby.
> > > 
> > > It have to be implemented for power == FB_BLANK_POWERDOWN to turn off
> > > the regulators of the lcd.
> > > 
> > > What do you think about?
> > 
> > Thanks! I sent a new (better) version. If you want credit in it, tell me
> > how should I add you one ;-)
> 
> Oh no, you have the credit on it. I admit that my L4F00242T03 is not my
> best driver, but soon I will work on it again ;)

You're very welcome, you did a great job!
> 
> Thank you for your fix!
> 
> Regards,