On 03/20/2016 08:15 PM, Hans de Goede wrote: > > I'm running Debian Jessie with Linux 4.3.0-0.bpo.1-armmp-lpae on my > > a20-olinuxino-lime2. > > I have noticed that my board hangs with my recent u-boot versions > when I > > load the i2c module. > > > > git-bisect narrowed the problem down to the following commit: > > > > 02cc27c74f9b884b538bcd1b93342a4c05b5d608 is the first bad commit > > commit 02cc27c74f9b884b538bcd1b93342a4c05b5d608 > > Author: Hans de Goede <hdegoede at redhat.com> > > Date: Sat Oct 3 15:29:24 2015 +0200 > > > > sunxi: power: Change axp209 LDO3 and LDO4 default to disabled > > <Snip> > > > The axp209 is attached to the i2c bus, so that is likely the real > > culprit. In my setup, the axp209 drivers are loaded before I insert > > i2c-mv64xxx. > > > > What would be the best course of action here? > > > > * Revert the commit > > * Enable LDO3 and LDO4 for the a20-olinuxino-lime2 only? > > * Fix linux > > I would go for option 3: "Fix linux", looking at the lime2 dts I see: > > vcc_csi0: ldo3 { > regulator-min-microvolt = <700000>; > regulator-max-microvolt = <3500000>; > regulator-always-on; > }; > > vcc_csi1: ldo4 { > regulator-min-microvolt = <1250000>; > regulator-max-microvolt = <3300000>; > regulator-always-on; > }; > > The regulator-always-on will cause both regulators to get turned on, > but the min / max constraints match the datasheet constrains / the > absolute min / max values these ldo-s can deliver, not the constraints > which the board design puts on these. > > So now these ldo-s end up getting turned on at whatever voltage > is the default (which according to the datasheet is unknown), > where as the schematic says that if these get turned on (which > is not necessary) they should be run at 2.8V. > > This dts file is the only axp209 using dts file which: > > 1) Does not have proper constraints for LDO3 / LDO4 > 2) Uses regulator-always-on; for these > > I would suggest fixing both, first you can try making min = max = > 2800000. And if that fixes things, which I expect it will, I would > also drop the regulator-always-on from the dts, since we really > only need to turn these on when using the csi interface in which > case it would be up to the csi driver to explicitly turn them on. >
Setting the voltage to 2.8V does not seem to fix things. Dropping the 'regulator-always-on' stance does allow me to load and use i2c-mv64xx and axp20x-i2c. Is that something I should submit upstream or is there further investigation needed why simply setting a proper voltage does not work? Thanks! Michael _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot