4.20-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 23b5f73266e59a598c1e5dd435d87651b5a7626b ]
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.
Signed-off-by: Badhri Jagan Sridharan badhri@google.com Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com --------- Version history: V3: Rebase on top of usb-next
V2: Based on feedback from heikki.krogerus@linux.intel.com - self_powered added to the struct tcpm_port which is populated from a. "connector" node of the device tree in tcpm_fw_get_caps() b. "self_powered" node of the tcpc_config in tcpm_copy_caps
Based on feedbase from linux@roeck-us.net - Code was refactored - SRC_HARD_RESET_VBUS_OFF sets the link state to false based on self_powered flag
V1 located here: https://lkml.org/lkml/2018/9/13/94 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/usb/typec/tcpm/tcpm.c | 12 ++++++++++-- include/linux/usb/tcpm.h | 1 + 2 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index dbbd71f754d0..ba6e5cdaed2c 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -317,6 +317,9 @@ 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 */ @@ -3254,7 +3257,8 @@ static void run_state_machine(struct tcpm_port *port) case SRC_HARD_RESET_VBUS_OFF: tcpm_set_vconn(port, true); 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: @@ -3267,7 +3271,8 @@ static void run_state_machine(struct tcpm_port *port) memset(&port->pps_data, 0, sizeof(port->pps_data)); 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 @@ -4412,6 +4417,8 @@ sink: return -EINVAL; port->operating_snk_mw = mw / 1000;
+ port->self_powered = fwnode_property_read_bool(fwnode, "self-powered"); + return 0; }
@@ -4720,6 +4727,7 @@ static int tcpm_copy_caps(struct tcpm_port *port, port->typec_caps.prefer_role = tcfg->default_role; port->typec_caps.type = tcfg->type; port->typec_caps.data = tcfg->data; + port->self_powered = port->tcpc->config->self_powered;
return 0; } diff --git a/include/linux/usb/tcpm.h b/include/linux/usb/tcpm.h index 7e7fbfb84e8e..50c74a77db55 100644 --- a/include/linux/usb/tcpm.h +++ b/include/linux/usb/tcpm.h @@ -89,6 +89,7 @@ struct tcpc_config { enum typec_port_data data; 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; };