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| author | Alec Berg <alecaberg@chromium.org> | 2015-01-22 18:30:09 -0800 |
|---|---|---|
| committer | ChromeOS Commit Bot <chromeos-commit-bot@chromium.org> | 2015-01-23 19:56:42 +0000 |
| commit | 35c00bf3d9a9dd5da6e797a189598ed4862626f5 (patch) | |
| tree | fabee62bf5be80a5e02c92d83509a6f4c591f5a1 | |
| parent | ad0306862031b4422958c1b7fc0b5399825f6d37 (diff) | |
| download | chrome-ec-35c00bf3d9a9dd5da6e797a189598ed4862626f5.tar.gz | |
pd: fix power swap to sink could get wedged if missing PS_RDY
Fix bug if we are executing a power swap to a sink, and we don't
get PS_RDY from port partner, then we transition to SNK_DISCONNECTED
without switching our power role to sink, which could cause us to
get wedged in the wrong state if we also receive a hard reset a
little later because we will have Rd asserted but are will transition
to source role and can never get out of it.
BUG=none
BRANCH=samus
TEST=load onto two samus' and executing a bunch of power swaps. load
custom code on one samus to never send PS_RDY when switching from sink
to source and make sure when power swap occurs the state machine does
not get wedged with the wrong role.
Change-Id: I7eb2bd4d48f32770b8d7a754fee8ac8da35fa949
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/242760
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>
| -rw-r--r-- | common/usb_pd_protocol.c | 14 |
1 files changed, 3 insertions, 11 deletions
diff --git a/common/usb_pd_protocol.c b/common/usb_pd_protocol.c index 234f024624..b7c190d173 100644 --- a/common/usb_pd_protocol.c +++ b/common/usb_pd_protocol.c @@ -833,12 +833,6 @@ static void execute_hard_reset(int port) pd_set_host_mode(port, 0); pd_power_supply_reset(port); } - /* - * If we are swapping to a sink and have changed to Rd, change role to - * sink to match the CC pull resistor. - */ - if (pd[port].task_state == PD_STATE_SRC_SWAP_STANDBY) - pd[port].power_role = PD_ROLE_SINK; if (pd[port].power_role == PD_ROLE_SINK) { /* Clear the input current limit */ @@ -2251,8 +2245,9 @@ void pd_task(void) PD_STATE_SRC_DISCONNECTED); break; } - /* Switch to Rd */ + /* Switch to Rd and swap roles to sink */ pd_set_host_mode(port, 0); + pd[port].power_role = PD_ROLE_SINK; /* Wait for PS_RDY from new source */ set_state_timeout(port, get_time().val + @@ -2698,10 +2693,7 @@ void pd_task(void) * If hard reset while in the last stages of power * swap, then we need to restore our CC resistor. */ - if (pd[port].last_state == PD_STATE_SRC_SWAP_STANDBY) - pd_set_host_mode(port, 1); - else if (pd[port].last_state == - PD_STATE_SNK_SWAP_STANDBY) + if (pd[port].last_state == PD_STATE_SNK_SWAP_STANDBY) pd_set_host_mode(port, 0); #endif |