linux-kernel - [PATCH 10/11 v3] staging: typec: tcpm: Do not send PING msgs in TCPM

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Date:   Mon, 28 Aug 2017 10:23:21 -0700
From:   Badhri Jagan Sridharan <badhri@...gle.com>
To:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Guenter Roeck <linux@...ck-us.net>
Cc:     devel@...verdev.osuosl.org, linux-kernel@...r.kernel.org,
        Badhri Jagan Sridharan <Badhri@...gle.com>
Subject: [PATCH 10/11 v3] staging: typec: tcpm: Do not send PING msgs in TCPM

PING messages are used to monitor the connect/disconnect.
However, when PD is carried over CC, so this is not required.

Also, the spec does not clearly say if PD is possible when
Type-c is connected to Type-A/B. So, removing sending
PING messages altogether.

Signed-off-by: Badhri Jagan Sridharan <Badhri@...gle.com>
Reviewed-by: Guenter Roeck <linux@...ck-us.net>
---
Changelog since previous version:
- Only one previous version of the patch was sent.
  Numbering this V3 instead of V2 to keep the sequence
  number in sync with the rest of the patches in the
  patch list.
- added Reviewed-by: Guenter Roeck <linux@...ck-us.net>
- fixed version/sequence numbers

 drivers/staging/typec/tcpm.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index a7da609006f5..9e0111dea7c4 100644
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -2335,14 +2335,11 @@ static void run_state_machine(struct tcpm_port *port)
 		 * - The system is not operating in PD mode
 		 * or
 		 * - Both partners are connected using a Type-C connector
-		 *   XXX How do we know that ?
+		 *
+		 * There is no actual need to send PD messages since the local
+		 * port type-c and the spec does not clearly say whether PD is
+		 * possible when type-c is connected to Type-A/B
 		 */
-		if (port->pwr_opmode == TYPEC_PWR_MODE_PD &&
-		    !port->op_vsafe5v) {
-			tcpm_pd_send_control(port, PD_CTRL_PING);
-			tcpm_set_state_cond(port, SRC_READY,
-					    PD_T_SOURCE_ACTIVITY);
-		}
 		break;
 	case SRC_WAIT_NEW_CAPABILITIES:
 		/* Nothing to do... */
-- 
2.14.1.342.g6490525c54-goog