Messages in this thread | | | Subject | Re: [BUG] i2c-hid: ELAN Touchpad does not work on ASUS X580GD | From | Jarkko Nikula <> | Date | Mon, 14 May 2018 17:20:22 +0300 |
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On 05/10/2018 03:03 PM, Chris Chiu wrote: > Report from guys who can access scope. If i2c-sda-falling-time-ns=400ns > , HCNT increase to 117, the SCL high duration is 576ns as follows > https://pasteboard.co/HkwERvP.png > > The original SCL high duration (HCNT = 105, 120MHz) is as follows > https://pasteboard.co/HkwFxgY.png > > So the HCNT does affect but per this HCNT/LCNT value, just not 400kHz > as expected. Any suggestion? > Thanks for measurements. I was sidetracked last week so I don't have yet explanation why signals run faster than expected :-(
Using 120 MHz SPT I2C clocks in commit b418bbff36dd ("mfd: intel-lpss: Add Intel Cannonlake PCI IDs") is clearly wrong but before going to 133 MHz (which work for you but still runs too fast) I would like to find explanation why it appears to be much higher.
-- Jarkko
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