staging: typec: tcpm: Fix Port Power Role field in PS_RDY messages

PS_RDY messages sent during power swap sequences are expected to reflect
the new power role.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index c749e980ddf97b6d6ebab2efa2df9afb2071df42..20eb4ebcf8c3dba29f03fa58fa09169c281bf27c 100644 (file)
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -2607,6 +2607,14 @@ static void run_state_machine(struct tcpm_port *port)
                break;
        case PR_SWAP_SRC_SNK_SOURCE_OFF:
                tcpm_set_cc(port, TYPEC_CC_RD);
+               /*
+                * USB-PD standard, 6.2.1.4, Port Power Role:
+                * "During the Power Role Swap Sequence, for the initial Source
+                * Port, the Port Power Role field shall be set to Sink in the
+                * PS_RDY Message indicating that the initial Source’s power
+                * supply is turned off"
+                */
+               tcpm_set_pwr_role(port, TYPEC_SINK);
                if (tcpm_pd_send_control(port, PD_CTRL_PS_RDY)) {
                        tcpm_set_state(port, ERROR_RECOVERY, 0);
                        break;
@@ -2614,7 +2622,6 @@ static void run_state_machine(struct tcpm_port *port)
                tcpm_set_state_cond(port, SNK_UNATTACHED, PD_T_PS_SOURCE_ON);
                break;
        case PR_SWAP_SRC_SNK_SINK_ON:
-               tcpm_set_pwr_role(port, TYPEC_SINK);
                tcpm_swap_complete(port, 0);
                tcpm_set_state(port, SNK_STARTUP, 0);
                break;
@@ -2626,8 +2633,15 @@ static void run_state_machine(struct tcpm_port *port)
        case PR_SWAP_SNK_SRC_SOURCE_ON:
                tcpm_set_cc(port, tcpm_rp_cc(port));
                tcpm_set_vbus(port, true);
-               tcpm_pd_send_control(port, PD_CTRL_PS_RDY);
+               /*
+                * USB PD standard, 6.2.1.4:
+                * "Subsequent Messages initiated by the Policy Engine,
+                * such as the PS_RDY Message sent to indicate that Vbus
+                * is ready, will have the Port Power Role field set to
+                * Source."
+                */
                tcpm_set_pwr_role(port, TYPEC_SOURCE);
+               tcpm_pd_send_control(port, PD_CTRL_PS_RDY);
                tcpm_swap_complete(port, 0);
                tcpm_set_state(port, SRC_STARTUP, 0);
                break;