Hi Heiko, On Fri, Jan 24, 2020 at 2:33 AM Heiko Schocher <h...@denx.de> wrote: > > Hello Fabio, Peng, > > I have here an imx6ull based board from DH electronics [1] > which has the IMX_THERMAL driver enabled in U-Boot and Linux. We > see on Linux boot random crashes (random means not on every boot, > also not even the same crash dump/reason in linux). My first > suggestion was instable RMA, but RAM seems stable. > > After some investigation it turned out, that setting the > REFTOP_SELBIASOFF bit in the linux thermal driver seems the problem. > > I saw that the kernel driver does not check first if REFTOP_VBGUP > is set and added this, but this did not helped. > > U-Boot does this check here: > > https://gitlab.denx.de/u-boot/u-boot/blob/master/arch/arm/mach-imx/mx6/soc.c#L342 > > More investigation into this problem and we found how U-Boot handles > this bit: > > U-Boot: sets this bit in arch_cpu_init() > U-Boot: sets this bit in IMX_THERMAL driver > U-Boot: clears this bit in IMX_THERMAL driver > > > If we now remove the clearing of this bit in U-Boot in the thermal > driver, we also see no crashes anymore in Linux (more than 12000 > power on/off cycles) > > My question is now, > > - do you now more about this bit as in the RM is described? > Or know somebody we can ask? > > - What effect has this bit? May it leads in more power consumption? > > - Is it valid to not clear it in U-Boot?
I was not aware of such problem and not familiar with these details. I think someone from NXP hardware team would have to take a look and confirm. Please post these question at the i.MX community forum: https://community.nxp.com/community/imx Thanks
