diff options
| author | Keith Short <keithshort@chromium.org> | 2020-08-27 14:51:41 -0600 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2020-09-02 03:20:23 +0000 |
| commit | c069177ccc29b4373d5587e1dcea966aeee0a856 (patch) | |
| tree | 84f6a1b6e046b0c2aab859a992a7366c5fb29c8c /common | |
| parent | 6b7a3e349d4d55c3a5a40bfa6094e415a5a4d8c3 (diff) | |
| download | chrome-ec-c069177ccc29b4373d5587e1dcea966aeee0a856.tar.gz | |
tcpmv2: disable receive of SOP' during VCONN swap
The USB PD specification indicates that the initial VCONN source shall
cease source VCONN within tVCONNSourceOff (25 ms) after receiving
PS_RDY. Not all partners wait after sending PS_RDY before trying to
communicate with the cable.
BUG=b:163478172, b:163143427
BRANCH=none
TEST=make buildall
TEST=Connect 2 Volteers together and force VCONN swaps confirming the
sequence completes normally.
Signed-off-by: Keith Short <keithshort@chromium.org>
Change-Id: I14720f033c5f6e9caed9c4fe3bfa11e5c046116e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2381030
Reviewed-by: Denis Brockus <dbrockus@chromium.org>
Commit-Queue: Denis Brockus <dbrockus@chromium.org>
Diffstat (limited to 'common')
| -rw-r--r-- | common/usbc/usb_pe_drp_sm.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/common/usbc/usb_pe_drp_sm.c b/common/usbc/usb_pe_drp_sm.c index c90d98a75c..7e76c15e1c 100644 --- a/common/usbc/usb_pe_drp_sm.c +++ b/common/usbc/usb_pe_drp_sm.c @@ -5269,6 +5269,23 @@ static void pe_vcs_evaluate_swap_entry(int port) /* NOTE: PE_VCS_Accept_Swap State embedded here */ PE_SET_FLAG(port, PE_FLAGS_ACCEPT); send_ctrl_msg(port, TCPC_TX_SOP, PD_CTRL_ACCEPT); + + /* + * The USB PD 3.0 spec indicates that the initial VCONN source + * shall cease sourcing VCONN within tVCONNSourceOff (25ms) + * after receiving the PS_RDY message. However, some partners + * begin sending SOP' messages only 1 ms after sending PS_RDY + * during VCONN swap. + * + * Preemptively disable receipt of SOP' and SOP'' messages while + * we wait for PS_RDY so we don't attempt to process messages + * directed at the cable. If the partner fails to send PS_RDY we + * perform a hard reset so no need to re-enable SOP' messages. + * + * We continue to source VCONN while we wait as required by the + * spec. + */ + tcpm_sop_prime_disable(port); } } @@ -5333,12 +5350,18 @@ static void pe_vcs_send_swap_run(int port) */ if (type == PD_CTRL_ACCEPT) { pe[port].vconn_swap_counter = 0; - if (tc_is_vconn_src(port)) + if (tc_is_vconn_src(port)) { + /* + * Prevent receiving any SOP' and SOP'' + * messages while a swap is in progress. + */ + tcpm_sop_prime_disable(port); set_state_pe(port, PE_VCS_WAIT_FOR_VCONN_SWAP); - else + } else { set_state_pe(port, PE_VCS_TURN_ON_VCONN_SWAP); + } return; } /* |