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authorWilliam wu <wulf@rock-chips.com>2016-09-29 15:18:41 +0800
committerPatrick Georgi <pgeorgi@google.com>2016-10-08 16:40:22 +0200
commit5b1bb3d980475a4af5b2feed078ec64437da2175 (patch)
tree0f162b7d3e8076dab6b9867711a480f00f2fd777 /src/superio/fintek
parent801a8ef2c3c209e0f44978b677f7b03cde209f21 (diff)
google/gru: Add USB 2.0 PHY tuning for Kevin PHY0 and PHY1
We found that Kevin board PHY0 and PHY1 eye-diagram margin is not enough to make compliance test pass, and the PHY0 USB SI is worse than PHY1, because of the higher PCB impedance. For PHY0, we can't improve the eye-diagram by SW PHY tuning, so we need to reduce the RBIAS resistance from 133 ohm to 115 ohm, it can help to increase the eye-height. For PHY1, we can improve the eye-diagram by setting the max pre-emphasis level. And after the above change, the USB2 signal amplitude will become larger at the test point near to SOC USB2 PHY, in order to avoid mis-trigger the disconnect detection (650mV), we need to disable pre-emphasize in eop state. BRANCH=None BUG=chrome-os-partner:53863 TEST=do USB 2.0 compliance test for Kevin C0 and C1 port. Change-Id: I95c0acd79623aeca9a0ae077b1dd3836d91fe561 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: de3cdef128966d76e7d8e2ebd641763b911c3ad5 Original-Change-Id: I00cb325b9938e4276cc77b5d6f5faa7023379608 Original-Signed-off-by: William wu <wulf@rock-chips.com> Original-Reviewed-on: https://chromium-review.googlesource.com/390615 Original-Commit-Ready: Julius Werner <jwerner@chromium.org> Original-Tested-by: Julius Werner <jwerner@chromium.org> Original-Reviewed-by: Julius Werner <jwerner@chromium.org> Reviewed-on: https://review.coreboot.org/16911 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth <martinroth@google.com>
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