Rockboxed Sansa Clip+ screen glitches

[kazekage]

Hello. I've been using rockbox for a while at my Clip+ without any troubles. But lately i've started to get video artifacts like those on the screens below. I think my problem could be hardware-related as i accidentally washed my Clip+ few days ago. But which is strange, when i boot into original sansa firmware it works perfectly fine, just the way it's been always working.




Can you please give me any suggestion to what can cause this behaviour? I've re-installed original firmware, rockbox and bootloader several times without any success. Thank you in advance.
Post Merge: March 18, 2012, 11:37:49 AMI've forgotten to mention that sometimes it happens that clip+ boots fine - without screen issuess. And when it happens i have no problems with menu like on the images above until I turn sansa off and then power on again.

[bertrik]

Not sure what causes this.
In the code I do see that we're not really careful in properly resetting the display controller. Perhaps a more thorough reset in the display code fixes the problem.

To make things slightly more complicated, there can be two different kinds of display in the clip+. Can you go into menu system/debug/View I/O ports and tell me the value of GPIOB?

[kazekage]

GPIOB: E4    DIR:E5

[bertrik]

Are you able to compile a test build, based on a patch I could write?

[kazekage]

I think I will be able to do that with the wiki guide assistance.

[bertrik]

I just committed a possible fix, to properly reset the display controller at bootup. Can you try the current build?

[kazekage]

Hello. Thank you for looking into this issue. I've installed rockbox current build dated 20.03.12 via RockboxUtility, however i'm still experiencing similar screen artifacts. Sometimes it boots fine several times in a row, then after some random power-on screen becomes buggy and often remains like that several times i turn it on after that.

[kazekage]

Hello again. Tested current build for a few days and eventually all issues disappered. I haven't seen any glitches like mentioned above for the past week. I have no idea what caused this behavior. Bertrik, thank you once again for helping me out.

[bertrik]

Besides the display reset fix, nothing was changed in the display driver recently.
I guess your player just dried out more thoroughly now

In theory, the clipv1, clipv2, clip+ display variant 0 and clip+ display variant 1 all could have different initialisation sequences, with for example different transfer speeds and resulting sensitivities to disturbance like moisture/contamination.
In practice, we initialise the clip+ display with the same setting that the clipv1 uses, with some special cases for the display that is in some clip+ players.