On 20/09/16 19:02, Paul Kocialkowski wrote: > * PGP Signed by an unknown key > > Le mardi 20 septembre 2016 à 18:40 +0100, Jon Hunter a écrit : >> On 28/08/16 18:32, Paul Kocialkowski wrote: >>> >>> Nyan boards come with an embedded controller that controls when to >>> enable and disable the charge. Thus, it should not be left up to the >>> kernel to handle that. >>> >>> Using the ti,external-control property allows specifying this use-case. >> >> So the bq24735 is populated under the EC's 'i2c-tunnel' property which >> is there to specifically interface it's child devices to the host. So I >> am a bit confused why this is expose to the host if it should not be used? > > Well, it needs to access the information in the read-only registers provided by > the chip, which is allowed by the setup in place that you described. Is this to expose the current state to the kernel so we can monitor the battery state? > However, the EC has its internal state machine that decides when to start > charging, etc and so should be the only one to write registers, to avoid > conflicts. > >> Again you may right and I did find the original series [0] for this >> which specifically references the Acer Chromebook that needs this. >> However, I am not sure why this was never populated? Is there any other >> history here? > > I am also confused about why it wasn't applied earlier. However, the cros kernel > is using the very same scheme. Do you have a reference? >> What is the actual problem you see without making this change? > > There is a risk of conflict (even though it's probably not that significant), > given the low variety of possible cases here. The idea is simply to say that the > EC is in charge and to let it do its job without interfering. > >> The original series states ... >> >> "On Acer Chromebook 13 (CB5-311) this module fails to load if the >> charger is not inserted, and will error when it is removed." > > I'm confused about that comment. At this point (and with this patch), it works > normally. Ok, I think Thierry prefers to only apply fixes for problems that can be reproduced. Is there a simple way to check the battery status and charging status via say the sysfs? If I can test that this has no negative impact may be it is ok. Cheers Jon -- nvpublic -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
