[PATCH 5.12 108/296] usb: typec: tcpm: Properly interrupt VDM AMS

Greg Kroah-Hartman
2021-05-31T16:16:19Z

From: Kyle Tso <kyletso@google.com>

commit 0bc3ee92880d910a1d100b73a781904f359e1f1c upstream.

When a VDM AMS is interrupted by Messages other than VDM, the AMS needs
to be finished properly. Also start a VDM AMS if receiving SVDM Commands
from the port partner to complement the functionality of tcpm_vdm_ams().

Fixes: 0908c5aca31e ("usb: typec: tcpm: AMS and Collision Avoidance")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20210523015855.1785484-2-kyletso@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/typec/tcpm/tcpm.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -1534,6 +1534,8 @@ static int tcpm_pd_svdm(struct tcpm_port
if (PD_VDO_SVDM_VER(p[0]) < svdm_version)
typec_partner_set_svdm_version(port->partner,
PD_VDO_SVDM_VER(p[0]));
+
+ tcpm_ams_start(port, DISCOVER_IDENTITY);
/* 6.4.4.3.1: Only respond as UFP (device) */
if (port->data_role == TYPEC_DEVICE &&
port->nr_snk_vdo) {
@@ -1552,14 +1554,19 @@ static int tcpm_pd_svdm(struct tcpm_port
}
break;
case CMD_DISCOVER_SVID:
+ tcpm_ams_start(port, DISCOVER_SVIDS);
break;
case CMD_DISCOVER_MODES:
+ tcpm_ams_start(port, DISCOVER_MODES);
break;
case CMD_ENTER_MODE:
+ tcpm_ams_start(port, DFP_TO_UFP_ENTER_MODE);
break;
case CMD_EXIT_MODE:
+ tcpm_ams_start(port, DFP_TO_UFP_EXIT_MODE);
break;
case CMD_ATTENTION:
+ tcpm_ams_start(port, ATTENTION);
/* Attention command does not have response */
*adev_action = ADEV_ATTENTION;
return 0;
@@ -2267,6 +2274,12 @@ static void tcpm_pd_data_request(struct
bool frs_enable;
int ret;

+ if (tcpm_vdm_ams(port) && type != PD_DATA_VENDOR_DEF) {
+ port->vdm_state = VDM_STATE_ERR_BUSY;
+ tcpm_ams_finish(port);
+ mod_vdm_delayed_work(port, 0);
+ }
+
switch (type) {
case PD_DATA_SOURCE_CAP:
for (i = 0; i < cnt; i++)
@@ -2439,6 +2452,16 @@ static void tcpm_pd_ctrl_request(struct
enum pd_ctrl_msg_type type = pd_header_type_le(msg->header);
enum tcpm_state next_state;

+ /*
+ * Stop VDM state machine if interrupted by other Messages while NOT_SUPP is allowed in
+ * VDM AMS if waiting for VDM responses and will be handled later.
+ */
+ if (tcpm_vdm_ams(port) && type != PD_CTRL_NOT_SUPP && type != PD_CTRL_GOOD_CRC) {
+ port->vdm_state = VDM_STATE_ERR_BUSY;
+ tcpm_ams_finish(port);
+ mod_vdm_delayed_work(port, 0);
+ }
+
switch (type) {
case PD_CTRL_GOOD_CRC:
case PD_CTRL_PING:
@@ -2697,6 +2720,13 @@ static void tcpm_pd_ext_msg_request(stru
enum pd_ext_msg_type type = pd_header_type_le(msg->header);
unsigned int data_size = pd_ext_header_data_size_le(msg->ext_msg.header);

+ /* stopping VDM state machine if interrupted by other Messages */
+ if (tcpm_vdm_ams(port)) {
+ port->vdm_state = VDM_STATE_ERR_BUSY;
+ tcpm_ams_finish(port);
+ mod_vdm_delayed_work(port, 0);
+ }
+
if (!(le16_to_cpu(msg->ext_msg.header) & PD_EXT_HDR_CHUNKED)) {
tcpm_pd_handle_msg(port, PD_MSG_CTRL_NOT_SUPP, NONE_AMS);
tcpm_log(port, "Unchunked extended messages unsupported");