From 2b4e0221d48c8ed522ce2bd19efbb222705ee6cd Mon Sep 17 00:00:00 2001 From: Badhri Jagan Sridharan Date: Mon, 1 Oct 2018 14:32:51 -0700 Subject: [PATCH] BACKPORT: usb: typec: tcpm: Do not disconnect link for self powered devices During HARD_RESET the data link is disconnected. For self powered device, the spec is advising against doing that. From USB_PD_R3_0 7.1.5 Response to Hard Resets Device operation during and after a Hard Reset is defined as follows: Self-powered devices Should Not disconnect from USB during a Hard Reset (see Section 9.1.2). Bus powered devices will disconnect from USB during a Hard Reset due to the loss of their power source. Tackle this by letting TCPM know whether the device is self or bus powered. This overcomes unnecessary port disconnections from hard reset. Also, speeds up the enumeration time when connected to Type-A ports. Bug: 112376366 Bug: 112296845 Change-Id: I833f89d34cbdba32c43ba43e7d8394385d419bc3 Signed-off-by: Badhri Jagan Sridharan --- drivers/usb/typec/tcpm.c | 10 ++++++++-- include/linux/usb/tcpm.h | 1 + 2 files changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/usb/typec/tcpm.c b/drivers/usb/typec/tcpm.c index 9e9d60e91ac9..18f7bcb20068 100644 --- a/drivers/usb/typec/tcpm.c +++ b/drivers/usb/typec/tcpm.c @@ -299,6 +299,9 @@ struct tcpm_port { /* Deadline in jiffies to exit src_try_wait state */ unsigned long max_wait; + /* port belongs to a self powered device */ + bool self_powered; + #ifdef CONFIG_DEBUG_FS struct dentry *dentry; struct mutex logbuffer_lock; /* log buffer access lock */ @@ -2765,7 +2768,8 @@ static void run_state_machine(struct tcpm_port *port) case SRC_HARD_RESET_VBUS_OFF: tcpm_set_vconn(port, false); tcpm_set_vbus(port, false); - tcpm_set_roles(port, false, TYPEC_SOURCE, TYPEC_HOST); + tcpm_set_roles(port, port->self_powered, TYPEC_SOURCE, + TYPEC_HOST); tcpm_set_state(port, SRC_HARD_RESET_VBUS_ON, PD_T_SRC_RECOVER); break; case SRC_HARD_RESET_VBUS_ON: @@ -2778,7 +2782,8 @@ static void run_state_machine(struct tcpm_port *port) case SNK_HARD_RESET_SINK_OFF: tcpm_set_vconn(port, false); tcpm_set_charge(port, false); - tcpm_set_roles(port, false, TYPEC_SINK, TYPEC_DEVICE); + tcpm_set_roles(port, port->self_powered, TYPEC_SINK, + TYPEC_DEVICE); /* * VBUS may or may not toggle, depending on the adapter. * If it doesn't toggle, transition to SNK_HARD_RESET_SINK_ON @@ -3868,6 +3873,7 @@ struct tcpm_port *tcpm_register_port(struct device *dev, struct tcpc_dev *tcpc) port->typec_caps.vconn_set = tcpm_vconn_set; port->typec_caps.try_role = tcpm_try_role; port->typec_caps.port_type_set = tcpm_port_type_set; + port->self_powered = tcpc->config->self_powered; port->partner_desc.identity = &port->partner_ident; port->port_type = tcpc->config->type; diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h index 185964e73ec3..c95b4c25fcef 100644 --- a/include/linux/usb/tcpm.h +++ b/include/linux/usb/tcpm.h @@ -93,6 +93,7 @@ struct tcpc_config { enum typec_port_type type; enum typec_role default_role; bool try_role_hw; /* try.{src,snk} implemented in hardware */ + bool self_powered; /* port belongs to a self powered device */ const struct typec_altmode_desc *alt_modes; };