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author | Brian Norris <briannorris@chromium.org> | 2016-09-21 18:16:54 -0700 |
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committer | Patrick Georgi <pgeorgi@google.com> | 2016-10-07 17:55:39 +0200 |
commit | e06a1b895c9905c53faaacf9286bafea7a3ef921 (patch) | |
tree | 7e968b363b363e0df399b8f0d552bf49a685625a /src/drivers/sil | |
parent | 5d0847f7571b4b76a38b9ef5276ec0967f664833 (diff) |
google/gru: drive WLAN_MODULE_RST# low as early as possible
GPIO1_B3 (WLAN_MODULE_RST#) defaults as a pull-up input, but it is also
"pulled up" by 1.8V_WLAN. However, 1.8V_WLAN remains low for some time
during early boot. This leaves the signal floating somewhere in the
middle.
This has two potential issues:
(1) we're leaking some power for some (hopefully) short period of time
(2) we are possibly screwing with the Wifi power sequence; we aren't
supposed to deassert PDn (i.e., MODULE_RST#) until all the rails
have fully ramped for some period of time
Neither of the above issues are likely to be significant, but it is nice
to fix, I expect.
BRANCH=gru
BUG=chrome-os-partner:54026
TEST=measure WLAN_MODULE_RST# on scope at boot time
Change-Id: Ia6af9ad6954ad8feeda33015e3f205842380939e
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: 0e890a2787bf034d3358a33fc88c2dd8078593ab
Original-Change-Id: I120e26ad0ca486a326874986e142dcaee965b62d
Original-Signed-off-by: Brian Norris <briannorris@chromium.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/388009
Original-Reviewed-by: Douglas Anderson <dianders@chromium.org>
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/16882
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Martin Roth <martinroth@google.com>
Diffstat (limited to 'src/drivers/sil')
0 files changed, 0 insertions, 0 deletions