General :: SGH-T959V / Aries Port Sleep Of Death (SoD)

While porting SGH-T959V to the aries kernel, we've ran into a rather nasty SoD.

Without further ado, here is what I see on the usb-uart:

Code:

[ 168.243223] (hpd_status = 0)++
[ 171.568772] wm8994_set_mic_bias: HWREV=13, on=0
[ 171.581786] PM: Syncing filesystems ... done.
[ 171.591614] Freezing user space processes ... (elapsed 0.01 seconds) done.
[ 171.614047] Freezing remaining freezable tasks ... (elapsed 0.01 seconds) done.
[ 171.633556] Suspending console(s) (use no_console_suspend to debug)

Then the device never comes back from suspend. The power button, nor any other button on the phone will wake the phone.

This issue does not happen if:

usb is plugged in a device that holds a wakelock, such as sdhc/mmc, is active. So: logging to sdcard So the only way for me to debug the issue is over usb-uart or internal uart (which I'm still working on trying to solder correctly).

My first assumption is that a gpio pin is set incorrectly, but I've spent the last 3 months tinkering around with gpio settings and got no where.

I've also tried enabling power management (both platform specific and generic) debugging, and followed the basic pm debugging documentation in the kernel.

I get zero information about which device is either failing to suspend or any evidence as to where I should look.

At first we suspected the ril (samsung-modemctl), but after I checked out a commit before that code was committed and disabled rild in our init.aries.rc, I was able to reproduce the issue. So that rules out ril/samsung-modemctl.

I'm was also thinking it might have been one of the gpio interrupt pins, and I went through each pin and tried changing settings with no change.