Maxime Ripard <maxime.rip...@free-electrons.com> writes: > Hi, > > On Wed, Jun 14, 2017 at 09:07:12AM +0200, Maxime Ripard wrote: >> On Tue, Jun 13, 2017 at 09:14:00AM -0700, Kevin Hilman wrote: >> > Maxime Ripard <maxime.rip...@free-electrons.com> writes: >> > >> > > On Tue, Jun 06, 2017 at 12:45:17PM -0700, Kevin Hilman wrote: >> > >> On Mon, May 22, 2017 at 12:44 AM, Maxime Ripard >> > >> <maxime.rip...@free-electrons.com> wrote: >> > >> > 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 >> > >> >> <khil...@baylibre.com> wrote: >> > >> >> > On Fri, Feb 10, 2017 at 12:42 AM, Maxime Ripard >> > >> >> > <maxime.rip...@free-electrons.com> 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 <r...@formelder.dk> >> > >> >> >> >> > >> >> >> 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. >> > >> >> > >> I'm now powering the board via the header (5V to the CHG-IN pin) and >> > >> it doesn't change anything. Still fails in the same way, and >> > >> reverting $SUBJECT defconfig patch makes it work again. >> > > >> > > I tried it today with sunxi_defconfig that has AXP20X_REGULATOR >> > > built-in as well. It can boot fine on my CHIP here. >> > >> > What about multi_v7_defconfig? >> >> It seems to work in our farm. >> >> It's lagging behind at the moment, so it hasn't been published yet, >> but here is the last multi_v7 boot. >> http://code.bulix.org/a43kkf-147625?raw > > A bit of an update for that. It turned out that our farm also had this > issue. We tried to power it through the 5V plug, and it didn't change > anything. > > After wasting way too much time on this, we started digging into it > today with Chen-Yu. > > We found out after enabling DEBUG_DRIVER that the last line was always > a cpufreq rate change. Removing the handle on the CPU regulator wasn't > changing anything, which left us with the other option: the clocks. > > It turns out that in 4.12 we also switched to a new clock framework > for the sun5i family. A few printk down the line, the clock > calculation were not propagated to the PLL, resulting in a CPU crash. > > Now, you might ask why it was crashing in multi_v7, and not in > sunxi_defconfig. The default governor in multi_v7 is ondemand, the one > in sunxi is performance, and therefore it never changes the CPU clock > rate. > > And I guess reverting the regulator option patch just prevented the > cpufreq-dt from probing since it was missing the CPU regulator > described in DT. > > I'll send a patch addressing this, cc'd to stable.
Yay, thanks spending the extra time to dig into it. Kevin
