[Arm-netbook] 15in laptop LCD up on PCB1

[Luke Kenneth Casson Leighton]

On Wed, Dec 2, 2015 at 2:49 PM, joem <joem at martindale-electric.co.uk> wrote:
> On Tue, 2015-12-01 at 16:05 +0000, Luke Kenneth Casson Leighton wrote:
>> http://rhombus-tech.net/community_ideas/laptop_15in/news/
>>
>> it's by no means perfect, but i have at least data on-screen.  i
>> suspect EM interference is causing the corruption
>
> Looks to me like a timing signals error from the CPU
> with the LCD driver chip trying to do its best to keep sync.

 it's as if the HSYNC - no matter what parameters are used - is
entirely missing.  so the LCD takes the very first bits of each line
and uses that as "sync".

> Need to check with a scope against the specs of the LCD and
> what the CPU is generating.

 yehh my scope's only a max of 75mhz (maplin's digital scope)

 and i can't ramp things down in order to check, because the 3.4
kernel sunxi lcd code changes the clk_div parameter when the dclk rate
is set lower, such that entirely different code is activated.

 tricky...

l.