On Sun, Jun 24, 2018 at 4:37 PM, Michael Mrozek EvilDragon@openpandora.org wrote:
On So, 2018-06-24 at 13:50 +0200, H. Nikolaus Schaller wrote:
Hi,
@hns: Can you boot the latest board revision that has been produced without a battery?
No. None of the boards I have can boot w/o battery, at least with my software setup. IMHO the problem is that MLO (SPL) doesn't enable high power in the bq24297. This is done in U-Boot. If I remember correctly, some very early boards without any keyboard backlight were able to boot without battery. So it might help to turn off the keyboard backlight (gpio8_230) in MLO (and maybe restart in U-Boot).
That might explain things, especially the reason it switches off as soon as they go to full brightness.
So try to change board/pandora/pyra+lc15/pyra+lc15.c line 51
#if defined(CONFIG_SPL_BUILD) {TIMER8_PWM_EVT, (PTD | IEN | M6)}, /* GPIO8_230: keyboard backlight - pulled low */ #else {TIMER8_PWM_EVT, (PTU | IEN | M6)}, /* GPIO8_230: keyboard backlight - pulled high */ #endif
I've tried this, now it loads u-boot successfully but dies before it reaches the point where it reprograms bq24297, just after printing "DRAM: 4 GiB". It seems to be dying in initr_malloc(), no idea why. A wild guess is that code in malloc init utilizes more CPU pipelines and RAM (as it's clearing memory) which uses more power, and that goes over the current limit.
Hm, it it hard to enable high power for the bq24297 in MLO? I mean, if we recompile the MLO anyways, why switch off the backlight instead of enabling high power mode (if that fixes it).
I've tried this too and it doesn't work (i2c errors), probably the needed i2c bus is not properly initialized yet in MLO.
Or maybe change the brightness of the backlight to lowest?
Needs working i2c (I guess?) which is not working from MLO.
GraÅžvydas