On Wed, Feb 28, 2024 at 12:05:12AM +0000, Badhri Jagan Sridharan wrote:
While commit 69f89168b310 ("usb: typec: tpcm: Fix issues with power being removed during reset") fixes the boot issues for bus powered devices such as LibreTech Renegade Elite/Firefly, it trades off the CC pins NOT being Hi-Zed during errory recovery (i.e PORT_RESET) for devices which are NOT bus powered(a.k.a self powered). This change Hi-Zs the CC pins only for self powered devices, thus preventing brown out for bus powered devices
Adhering to spec is gaining more importance due to the Common charger initiative enforced by the European Union.
Quoting from the spec: 4.5.2.2.2.1 ErrorRecovery State Requirements The port shall not drive VBUS or VCONN, and shall present a high-impedance to ground (above zOPEN) on its CC1 and CC2 pins.
Hi-Zing the CC pins is the inteded behavior for PORT_RESET. CC pins are set to default state after tErrorRecovery in PORT_RESET_WAIT_OFF.
4.5.2.2.2.2 Exiting From ErrorRecovery State A Sink shall transition to Unattached.SNK after tErrorRecovery. A Source shall transition to Unattached.SRC after tErrorRecovery.Fixes: 69f89168b310 ("usb: typec: tpcm: Fix issues with power being removed during reset") Cc: stable@vger.kernel.org Cc: Mark Brown broonie@kernel.org Signed-off-by: Badhri Jagan Sridharan badhri@google.com
Acked-by: Heikki Krogerus heikki.krogerus@linux.intel.com
Changes since V1:
- Fix CC for linux stable
drivers/usb/typec/tcpm/tcpm.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index c9a78f55ca48..bbe1381232eb 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -5593,8 +5593,11 @@ static void run_state_machine(struct tcpm_port *port) break; case PORT_RESET: tcpm_reset_port(port);
tcpm_set_cc(port, tcpm_default_state(port) == SNK_UNATTACHED ?TYPEC_CC_RD : tcpm_rp_cc(port));
if (port->self_powered)tcpm_set_cc(port, TYPEC_CC_OPEN);elsetcpm_set_cc(port, tcpm_default_state(port) == SNK_UNATTACHED ?TYPEC_CC_RD : tcpm_rp_cc(port));base-commit: a560a5672826fc1e057068bda93b3d4c98d037a2
2.44.0.rc1.240.g4c46232300-goog