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authorWilliam wu <wulf@rock-chips.com>2017-01-09 19:02:39 +0800
committerMartin Roth <martinroth@google.com>2017-01-13 17:40:39 +0100
commit605a87c8eb8672375f2a58191fe7ba8ebc83c42a (patch)
tree3d226bca65dab79974fa066cb17fe79ad8c12476 /Documentation
parent9a3f06d202c2aab4809296bb62f3f573133f317c (diff)
gru: Tuning USB 2.0 PHY0 and PHY1 host-port
The commit 0ba3b2593b0c ("gru: Tuning USB 2.0 PHY to increase compatibility") bypass ODT to set the max driver strength for the Type-C otg-port, it works well on otg-port when connected with USB2.0 devices. Unfortunately, because the Type-C otg-port and host-port are consisted in one USB2 PHY, so bypass ODT will have an effect on both host-port and otg-port. I have tested the host-port eye-diagram, the result shows that if we bypass ODT, the host- port eye-diagram height will become to high, more than 500mv, this may cause USB 2.0 high-speed enumeration failure. This patch bypass ODT for host-port separately, and then we can reduce the host-port driver strength without affecting the otg-port driver strength. BRANCH=gru BUG=chrome-os-partner:60727 TEST=Boot system, run 'lsusb' command and check if the usb camera and usb bluetooth are on usb 2.0 hub or usb 1.1 hub. If they are on usb 1.1 hub, the issue happens. If not, try to run camera app and then close camera app, repeat until find that the usb camera is on the usb 1.1 hub. Change-Id: Ib693e2a6f2113c06692a7bfee22d85b67ee3b165 Signed-off-by: Patrick Georgi <pgeorgi@chromium.org> Original-Commit-Id: 5ea7660b7b05080b76fc5ca5af3fa18552a03491 Original-Change-Id: Ia1f12182929673c5726df9f77f0903469b5c957a Original-Signed-off-by: William wu <wulf@rock-chips.com> Original-Reviewed-on: https://chromium-review.googlesource.com/425739 Original-Commit-Ready: Douglas Anderson <dianders@chromium.org> Original-Tested-by: Douglas Anderson <dianders@chromium.org> Original-Tested-by: Inno Park <ih.yoo.park@samsung.com> Original-Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-on: https://review.coreboot.org/18126 Tested-by: build bot (Jenkins) Reviewed-by: Martin Roth <martinroth@google.com>
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