MT6755 uses R63350 IC to wake up to probabilistic flash white and causes ESD FAIL

Description of the phenomenon.

The phone automatically off the screen after pressing the Power key or home button to light the screen, the probability of a white one above, and will flash two or three lower screen.
The LCM IC used is: r63350, (FHD VDO) screen, accessories for mtklog See what is the reason?

Dear Custom:

If you close the ESD check, the problem appears to be improving.

Is it possible to help put the frontporch in a larger test?

Thank you

1. Increase Vertical_frontporch
Params->dsi.vertical_frontporch = 24;

Hi MTK:

Individually modified params->dsi.vertical_frontporch = 24; Validation has been reproduced to this phenomenon.
Close the ESD check mechanism, not yet tested to the splash screen phenomenon, but not very sure that will appear later.

Here the FAE has the following questions: Because of the wake up of the anomaly, vendor has 2 points of suspicion
1. The image is not displayed properly in the Wake screen (normal operation), will the ESD check go ahead and check the screen status?
2.lcm_resume How long does the ESD check have a detection action? Can you postpone it a little bit? Open the ESD detection thread.

Dear Custom:

Let's just experiment with other vendor IC experiences

In general, other vendor are provided with other registers as ESD reg check

Only RSP can read 0x0A.

General 0x0A Reg is only at the first time to confirm that the Panel has not been connected to use

and experience the time needed to stabilize the RSP DDIC 0x0A.

If RSP insists only on 0x0A when it is an ESD read reg check

Only through delay wait for RSP DDIC reg 0x0A Stable

But other vendor DDIC don't have this limitation .....

For the reference of the Department of Precious

Dear Customer

The inner part also discussed an experiment with delayed ESD check

Trouble first to change the code of the previous suggestion (Resume/suspend function "After the Light screen command after the" add some delay) first block out

Primary_display_check_recovery_worker_kthread (void *data) function in disp_recovery.c

Add the following delay code to try to see

Thank you


/* 1. ESD Check & Recovery */
if (esd_check_enable) {

i = 0;/*repeat*/
do {

Mdeay (100); Add by MTK

ret = Primary_display_esd_check ();

if (ret = = 1) {
Disperr ("[esd]esd check fail, would do ESD recovery. Try=%d\n ", i);
Primary_display_esd_recovery ();
Recovery_done = 1;
} else
Break

} while (++i < esd_try_cnt);

Flash white screen This piece can let vendor check the root cause, see if you can open the backlight by delay, or other ways to modify!

MT6755 uses R63350 IC to wake up to probabilistic flash white and causes ESD FAIL