i.mx28上电时屏幕闪烁问题如何解决

[ctspotgreen]

1.i.mx287的板子在上电时屏幕会闪几下，之后就正常了，这个问题该如何解决

2.如何使用MPU模式驱动LCD

[YixingKong]

Green, is this issue from a customer? If yes, please provide the customer's name.

Thanks,

Yixing

[YixingKong]

JackLee1z, could you have a look at this issue?

Thanks,

Yixing

[YixingKong]

JackLee1z, could you please help this one or need help?

Thanks,

Yixing

[alfred_liu]

YixingKong

我相信这个是一个软件配置的问题。

不确定是否FSL的开发板也有这个问题。

可以involve software AE 来看一下这个问题。

[ctspotgreen]

核心板是从周立功那买的，每块板子都这样，我也反映过问题，但是他们说原厂的也这样，没给出具体解决方案

[ctspotgreen]

包括他们的开发板也是这样的

[JackLee1z]

Please check if the LCD is initialized more than 1 times after bootup. Usually, it is happened in u-boot and kernel. When the LCD is initialized, the display buffer will be erased in common practice. Then, you could see the flicking in the panel.

BR,

Jack

[ctspotgreen · Accepted solution]

解决了，不是由于反复初始化LCD造成的闪屏，而是由于mxsfb_notifier()函数被内核频繁调用引起的，该函数直接return NOTIFY_DONE即可解决

[ctspotgreen]

mxsfb.c的probe()函数对于lcd的frame buffer的分配只执行了一次，pentry->init_panel(...)执行了2次,一次是通过enable_controller()调用实现,另一次直接调用实现,但是注释任意一段代码都无法正常初始化LCD，连VSYNC/HSYNC的波形都没有

此外如果menuconfig中Device Driver中取消USB SUPPORT将不再闪屏,也没有找到关于PWM引脚的相关控制代码

[alfred_liu]

Hi, Green

why the LCD fliker?

it's backlight issue? PWM issue? or the power issue? or the signals issue?

did you do some measurement?

[ctspotgreen]

就是在内核启动，企鹅图标出现的时候每次都会闪3下,背光是接死的，不存在PWM的问题，感觉是内核对LCD反复初始化导致帧不连续，从而出现闪烁现象