The Type-C protocol manager state machine could fail, which might result
in role swap requests from user space to hang forever. Add a generous
timeout when waiting for role swaps to complete to avoid this situation.
Originally-from: Badhri Jagan Sridharan <bad...@google.com>
Signed-off-by: Guenter Roeck <li...@roeck-us.net>
---
drivers/staging/typec/tcpm.c | 21 +++++++++++++++------
drivers/staging/typec/tcpm.h | 3 ++-
2 files changed, 17 insertions(+), 7 deletions(-)
diff --git a/drivers/staging/typec/tcpm.c b/drivers/staging/typec/tcpm.c
index cf498c68c4af..515bec1807d7 100644
--- a/drivers/staging/typec/tcpm.c
+++ b/drivers/staging/typec/tcpm.c
@@ -3166,9 +3166,12 @@ static int tcpm_dr_set(const struct typec_capability
*cap,
tcpm_set_state(port, DR_SWAP_SEND, 0);
mutex_unlock(&port->lock);
- wait_for_completion(&port->swap_complete);
+ if (!wait_for_completion_timeout(&port->swap_complete,
+ msecs_to_jiffies(PD_ROLE_SWAP_TIMEOUT)))
+ ret = -ETIMEDOUT;
+ else
+ ret = port->swap_status;
- ret = port->swap_status;
goto swap_unlock;
port_unlock:
@@ -3223,9 +3226,12 @@ static int tcpm_pr_set(const struct typec_capability
*cap,
tcpm_set_state(port, PR_SWAP_SEND, 0);
mutex_unlock(&port->lock);
- wait_for_completion(&port->swap_complete);
+ if (!wait_for_completion_timeout(&port->swap_complete,
+ msecs_to_jiffies(PD_ROLE_SWAP_TIMEOUT)))
+ ret = -ETIMEDOUT;
+ else
+ ret = port->swap_status;
- ret = port->swap_status;
goto swap_unlock;
port_unlock:
@@ -3260,9 +3266,12 @@ static int tcpm_vconn_set(const struct typec_capability
*cap,
tcpm_set_state(port, VCONN_SWAP_SEND, 0);
mutex_unlock(&port->lock);
- wait_for_completion(&port->swap_complete);
+ if (!wait_for_completion_timeout(&port->swap_complete,
+ msecs_to_jiffies(PD_ROLE_SWAP_TIMEOUT)))
+ ret = -ETIMEDOUT;
+ else
+ ret = port->swap_status;
- ret = port->swap_status;
goto swap_unlock;
port_unlock:
diff --git a/drivers/staging/typec/tcpm.h b/drivers/staging/typec/tcpm.h
index 4c6b38cb2c8a..374cea44a84a 100644
--- a/drivers/staging/typec/tcpm.h
+++ b/drivers/staging/typec/tcpm.h
@@ -34,7 +34,8 @@ enum typec_cc_polarity {
};
/* Time to wait for TCPC to complete transmit */
-#define PD_T_TCPC_TX_TIMEOUT 100
+#define PD_T_TCPC_TX_TIMEOUT 100 /* in ms */
+#define PD_ROLE_SWAP_TIMEOUT (MSEC_PER_SEC * 10)
enum tcpm_transmit_status {
TCPC_TX_SUCCESS = 0,
--
2.7.4
_______________________________________________
devel mailing list
de...@linuxdriverproject.org
http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
