From 9adf9f9ee71a6acb017922946ba1b8b2b2cff550 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 10 Aug 2017 21:15:43 -0700 Subject: [PATCH] staging: typec: tcpm: Add timeout when waiting for role swap completion 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 Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman --- 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 ac08364e86a6..8d3a9ad118aa 100644 --- a/drivers/staging/typec/tcpm.c +++ b/drivers/staging/typec/tcpm.c @@ -3165,9 +3165,12 @@ 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: @@ -3222,9 +3225,12 @@ 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: @@ -3259,9 +3265,12 @@ 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, -- 2.20.1