On 4/3/19 12:16 AM, Christopher Heiny wrote: > On Thu, 2019-03-28 at 14:02 +0800, Aaron Ma wrote: >> Hi Dmitry and Chiristopher: >> >> Do you have any suggestion about these 2 patches? >> >> Many users confirmed that they fixed issues of Trackpoint/Touchpad >> after S3. >> >> Will you consider them be accepted? > Hi Aaron, > > Sorry - I thought I'd replied on the NO SLEEP portion of these patches, > but looking back I don't find the draft or the sent email. Sorry about > that. I'll summarize here what I wrote last month. > > This isn't so much a "fix" as a "hacky workaround" for the issue. From > the descriptions in the bug you linked in your original patch > submission, it appears that the root cause is somewhere in SMBus system > (could be SMBus driver, SMBus hardware, or the devices on the SMBus > (touch devices or other devices) - it's hard to tell with the info > available), where the SMBus is failing to come online correctly coming > out of S3 state. Anyway, this patch doesn't fix the root cause, but > merely works around it. Users confirmed the 1st patch that clear irq status fixed their multiple issues on Touchpad and Trackpoint. I think it is a fix. NO SLEEP patch was tried to give users a choice a fix touchpad issues that I didn't reproduce. If you don't like this export, we can drop it now as users confirmed 1st patch works. > > Setting the NO SLEEP bit will force the touch sensor to remain in a > high power consumption state while the rest of the system is in S3. > While not a lot of power compared to things like the CPU, display, and > others, it is still non-trivial and will result in shorter time-on- > battery capability. Verified on s2idle and S3 and system running idle mode. no difference on power consumption of whole system with or without set 1 to nosleep. > > If you have access to the power pin(s) for the touch sensor(s)/styk(s), > it might be interesting to try turning power off on entering S3, and > restoring it on exit. That's very hacky, and has the side effect of > slightly delaying touchpad readiness on exit from S3. Plus you'll need > to restore touch sensor configuration settings on exit. But it > definitely reduces power consumption. > > > Separately, I am still concerned about the possibility of dropped touch > events in the IRQ clearing. I'm not convinced that the code is safe > (as you mentioned in your reply to my earlier comment), so I'll have to > study the implementation more carefully. Sure, take your time, if you have any questions let me know please. Thanks, Aaron > > Cheers, > Chris > > > >> Thanks, >> Aaron >
