From: Xu Yang xu.yang_2@nxp.com
commit abfc4fa28f0160df61c7149567da4f6494dfb488 upstream.
Since both source and sink device can send discover_identity message in PD3, kernel may dump below warning:
------------[ cut here ]------------ WARNING: CPU: 0 PID: 169 at drivers/usb/typec/tcpm/tcpm.c:1446 tcpm_queue_vdm+0xe0/0xf0 Modules linked in: CPU: 0 PID: 169 Comm: 1-0050 Not tainted 6.1.1-00038-g6a3c36cf1da2-dirty #567 Hardware name: NXP i.MX8MPlus EVK board (DT) pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : tcpm_queue_vdm+0xe0/0xf0 lr : tcpm_queue_vdm+0x2c/0xf0 sp : ffff80000c19bcd0 x29: ffff80000c19bcd0 x28: 0000000000000001 x27: ffff0000d11c8ab8 x26: ffff0000d11cc000 x25: 0000000000000000 x24: 00000000ff008081 x23: 0000000000000001 x22: 00000000ff00a081 x21: ffff80000c19bdbc x20: 0000000000000000 x19: ffff0000d11c8080 x18: ffffffffffffffff x17: 0000000000000000 x16: 0000000000000000 x15: ffff0000d716f580 x14: 0000000000000001 x13: ffff0000d716f507 x12: 0000000000000001 x11: 0000000000000000 x10: 0000000000000020 x9 : 00000000000ee098 x8 : 00000000ffffffff x7 : 000000000000001c x6 : ffff0000d716f580 x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000 x2 : ffff80000c19bdbc x1 : 00000000ff00a081 x0 : 0000000000000004 Call trace: tcpm_queue_vdm+0xe0/0xf0 tcpm_pd_rx_handler+0x340/0x1ab0 kthread_worker_fn+0xcc/0x18c kthread+0x10c/0x110 ret_from_fork+0x10/0x20 ---[ end trace 0000000000000000 ]---
Below sequences may trigger this warning:
tcpm_send_discover_work(work) tcpm_send_vdm(port, USB_SID_PD, CMD_DISCOVER_IDENT, NULL, 0); tcpm_queue_vdm(port, header, data, count); port->vdm_state = VDM_STATE_READY;
vdm_state_machine_work(work); <-- received discover_identity from partner vdm_run_state_machine(port); port->vdm_state = VDM_STATE_SEND_MESSAGE; mod_vdm_delayed_work(port, x);
tcpm_pd_rx_handler(work); tcpm_pd_data_request(port, msg); tcpm_handle_vdm_request(port, msg->payload, cnt); tcpm_queue_vdm(port, response[0], &response[1], rlen - 1); --> WARN_ON(port->vdm_state > VDM_STATE_DONE);
For this case, the state machine could still send out discover identity message later if we skip current discover_identity message. So we should handle the received message firstly and override the pending discover_identity message without warning in this case. Then, a delayed send_discover work will send discover_identity message again.
Fixes: e00943e91678 ("usb: typec: tcpm: PD3.0 sinks can send Discover Identity even in device mode") cc: stable@vger.kernel.org Signed-off-by: Xu Yang xu.yang_2@nxp.com Reviewed-by: Guenter Roeck linux@roeck-us.net Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Link: https://lore.kernel.org/r/20230216031515.4151117-1-xu.yang_2@nxp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/typec/tcpm/tcpm.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-)
--- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1436,10 +1436,18 @@ static int tcpm_ams_start(struct tcpm_po static void tcpm_queue_vdm(struct tcpm_port *port, const u32 header, const u32 *data, int cnt) { + u32 vdo_hdr = port->vdo_data[0]; + WARN_ON(!mutex_is_locked(&port->lock));
- /* Make sure we are not still processing a previous VDM packet */ - WARN_ON(port->vdm_state > VDM_STATE_DONE); + /* If is sending discover_identity, handle received message first */ + if (PD_VDO_SVDM(vdo_hdr) && PD_VDO_CMD(vdo_hdr) == CMD_DISCOVER_IDENT) { + port->send_discover = true; + mod_send_discover_delayed_work(port, SEND_DISCOVER_RETRY_MS); + } else { + /* Make sure we are not still processing a previous VDM packet */ + WARN_ON(port->vdm_state > VDM_STATE_DONE); + }
port->vdo_count = cnt + 1; port->vdo_data[0] = header; @@ -1942,11 +1950,13 @@ static void vdm_run_state_machine(struct switch (PD_VDO_CMD(vdo_hdr)) { case CMD_DISCOVER_IDENT: res = tcpm_ams_start(port, DISCOVER_IDENTITY); - if (res == 0) + if (res == 0) { port->send_discover = false; - else if (res == -EAGAIN) + } else if (res == -EAGAIN) { + port->vdo_data[0] = 0; mod_send_discover_delayed_work(port, SEND_DISCOVER_RETRY_MS); + } break; case CMD_DISCOVER_SVID: res = tcpm_ams_start(port, DISCOVER_SVIDS); @@ -2029,6 +2039,7 @@ static void vdm_run_state_machine(struct unsigned long timeout;
port->vdm_retries = 0; + port->vdo_data[0] = 0; port->vdm_state = VDM_STATE_BUSY; timeout = vdm_ready_timeout(vdo_hdr); mod_vdm_delayed_work(port, timeout);