Hi Kevin, On Thu, May 18, 2017 at 11:59:50AM -0700, Kevin Hilman wrote: > On Fri, Mar 17, 2017 at 10:39 AM, Kevin Hilman wrote: > > On Fri, Feb 10, 2017 at 12:42 AM, Maxime Ripard > > wrote: > >> On Wed, Feb 08, 2017 at 11:09:31PM +0100, Rask Ingemann Lambertsen wrote: > >>> The AXP20X regulator support is currently built as a module, which means > >>> it's not available until the root fs has been mounted, but the boot loader > >>> might not have enabled the required regulators, so build their drivers > >>> into the kernel. > >>> > >>> Signed-off-by: Rask Ingemann Lambertsen > >> > >> Queued for 4.12. > > > > Hello, kernelci.org is reporting boot failures on sun5i-r8-chip in > > linux-next[1] for a few days and with a variety of defconfigs. I > > bisected it[2] down to this patch. > > > > I verified that reverting this patch on top of next-20170310 makes my > > chip board boot again. > > FYI... this board is still broken in linux-next (and now in mainline), > and reverting $SUBJECT patch still makes it work. > > Is nobody else using mainline on this board? I thought about that during the weekend, and it might just be a symptom. The CHIP has brown out issues, especially when you enable the WiFi chip, which should happen around the time of the failure when the PMIC regulator support is compiled as a module. We mitigate that in upstream's U-Boot by enabling the two regulators for the WiFi chip in U-boot, which levels a bit the current over the boot. You have a few ways to prevent that from happening. Having a better power supply / cable will help, I'm not sure how reasonable that is. Another thing that can work is, if your USB plugs can take it, to increase the overcurrent trigger in the PMIC, ideally in U-Boot. The last, and probably cleaner one, would be to just power it through the 5v input on its header, and not the USB. There's not current limitation there, so it shouldn't cause any problems anymore. Maxime -- Maxime Ripard, Free Electrons Embedded Linux and Kernel engineering http://free-electrons.com