On Tue, Feb 17, 2015 at 6:45 PM, Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote: > On 02/17/15 15:02, Bjorn Andersson wrote: >> On Thu, Feb 12, 2015 at 8:26 PM, Stephen Boyd <sboyd@xxxxxxxxxxxxxx> wrote: [..] >>> This doesn't seem to do anything for the OVP spike mentioned in this >>> patch[1]. Do you see that problem on your device? I imagine the PMIC is >>> the same. >>> >>> [1] >>> https://www.codeaurora.org/cgit/quic/la/kernel/msm/commit/?id=fef9e15072562f0f28dc7066dcdd69388df81ed3 >>> >> That's odd, I can't find that fix in any officially supported releases >> for 8974 - which Courtney used as reference for this driver. >> >> Just to make sure I understand the solution; when disabling the sinks >> the over-voltage-protection sometimes triggers, so we should detect >> that and reset the ovp configuration? >> >> I presume the side effect would be that the sinks would not give any >> output until this is done? >> > > It seems that commit is not very good at describing the problem. From > what I can tell, the inductor current may spike when the WLED is turned > off and the switch is stuck on (the circuit is a boost convertor). To > make sure this doesn't happen, we force an OVP so that the switch is > known to be open (i.e. off) and thus can't cause the current spike when > we disable. > Apparently that commit is only half of the solution, there's another commit earlier in history with the same commit message [2]. With both [1] and [2] in place there are a bunch of different operations going on, so I'm not able to fully map these to your description - which does make sense. [2] https://www.codeaurora.org/cgit/quic/la/kernel/msm/commit/?id=b1a2f61113c69d2aba68c583101ac40a05cb2c5b Regards, Bjorn -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
