Hello Tomi,
On Fri, Mar 11, 2016 at 01:22:40PM +0200, Tomi Valkeinen wrote:
On 07/03/16 21:53, Uwe Kleine-König wrote:
quoted
This asserts that the display is on after the driver is initialized.
Otherwise, depending on how the boot loader handled the display, it is
either disabled as the regulator doesn't seem in use, or it stays off.
Signed-off-by: Uwe Kleine-König <redacted>
---
drivers/video/fbdev/imxfb.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/video/fbdev/imxfb.c b/drivers/video/fbdev/imxfb.c
index c5fcedde2a60..3dd2824e6773 100644
--- a/drivers/video/fbdev/imxfb.c
+++ b/drivers/video/fbdev/imxfb.c
@@ -979,8 +979,17 @@ static int imxfb_probe(struct platform_device *pdev)
imxfb_enable_controller(fbi);
fbi->pdev = pdev;
+ if (!IS_ERR(fbi->lcd_pwr)) {
+ ret = regulator_enable(fbi->lcd_pwr);
+ if (ret)
+ goto failed_regulator;
+ }
+
return 0;
+failed_regulator:
+ imxfb_disable_controller(fbi);
+
failed_lcd:
unregister_framebuffer(info);
So I didn't go through the code in detail, but this doesn't look correct
to me.
Where is the regulator disabled which now gets enabled in probe?
It isn't, the display should be on after all :-)
imxfb_lcd_set_power() handles the regulator enable/disable, so doesn't
this mean the regulator would always be enabled? You first enable it in
probe, then imxfb_lcd_set_power() enables it at some point (?), so the
enable-count is two then.
imxfb_lcd_set_power isn't called during boot.
To be honest, I've never used 'struct lcd_ops', but I think the enabling
of the regulator should happen somehow via that. If the regulator needs
to be enabled at probe time, then the probe should somehow cause
lcd_ops->set_power to get called.
Why does the regulator need to be enabled at probe? Or are you saying
imxfb_lcd_set_power() is never called in your case?
Right. I just confirmed that with next-20160419 with this patch on top:
diff --git a/drivers/video/fbdev/imxfb.c b/drivers/video/fbdev/imxfb.c
index 76b6a7784b06..93b803ebd61d 100644
--- a/drivers/video/fbdev/imxfb.c
+++ b/drivers/video/fbdev/imxfb.c
@@ -1,3 +1,4 @@
+#define DEBUG
/*
* Freescale i.MX Frame Buffer device driver
*
@@ -768,6 +769,7 @@ static int imxfb_lcd_set_power(struct lcd_device *lcddev, int power)
{
struct imxfb_info *fbi = dev_get_drvdata(&lcddev->dev);
+ dev_dbg(&lcddev->dev, "%s(power=%d)\n", __func__, power);
if (!IS_ERR(fbi->lcd_pwr)) {
if (power)
return regulator_enable(fbi->lcd_pwr);
With that:
# dmesg | grep -iE '(lcd|fb|power)'
[ 0.562633] backlight supply power not found, using dummy regulator
[ 0.568246] imx-fb 53fbc000.lcdc: i.MX Framebuffer driver
[ 0.568326] imxfb_init_fbinfo
[ 0.576275] Enabling LCD controller
[ 1.652166] sdhci-esdhc-imx 53fb4000.esdhc: Got CD GPIO
[ 1.658109] sdhci-esdhc-imx 53fb4000.esdhc: Got WP GPIO
[ 1.703638] mmc0: SDHCI controller on 53fb4000.esdhc [53fb4000.esdhc] using DMA
[ 4.094923] lcd supply: disabling
The bootloader enables the lcd before booting into Linux, with the last
message the display gets disabled.
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | http://www.pengutronix.de/ |