From c413767e6698ae24ac1904827314470cacff1497 Mon Sep 17 00:00:00 2001
From: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Date: Tue, 17 Jul 2018 15:36:19 +0100
Subject: [PATCH] usb: typec: tcpm: Fix sink PDO starting index for PPS APDO
 selection
Git-commit: c413767e6698ae24ac1904827314470cacff1497
References: FATE#326325
Patch-mainline: v4.18

There is a bug in the sink PDO search code when trying to select
a PPS APDO. The current code actually sets the starting index for
searching to whatever value 'i' is, rather than choosing index 1
to avoid the first PDO (always 5V fixed). As a result, for sources
which support PPS but whose PPS APDO index does not match with the
supporting sink PPS APDO index for the platform, no valid PPS APDO
will be found so this feature will not be permitted.

Sadly in testing, both Source and Sink capabilities matched up and
this was missed. Code is now updated to correctly set the start
index to 1, and testing with additional PPS capable sources show
this to work as expected.

Signed-off-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Fixes: 2eadc33f40d4 ("typec: tcpm: Add core support for sink side PPS")
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/typec/tcpm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c
index 150f43668bec..d1d20252bad8 100644
--- a/drivers/usb/typec/tcpm.c
+++ b/drivers/usb/typec/tcpm.c
@@ -2140,7 +2140,7 @@ static unsigned int tcpm_pd_select_pps_apdo(struct tcpm_port *port)
 			 * PPS APDO. Again skip the first sink PDO as this will
 			 * always be 5V 3A.
 			 */
-			for (j = i; j < port->nr_snk_pdo; j++) {
+			for (j = 1; j < port->nr_snk_pdo; j++) {
 				pdo = port->snk_pdo[j];
 
 				switch (pdo_type(pdo)) {
-- 
2.16.4