Re: [PATCH] usb: typec: tcpm: Fix altmode re-registration causes sysfs create fail
From: Macpaul Lin
Date: Thu Dec 15 2022 - 04:58:52 EST
On 12/15/22 17:21, cy_huang wrote:
From: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
There's the altmode re-registeration issue after data role
swap (DR_SWAP).
Comparing to USBPD 2.0, in USBPD 3.0, it loose the limit that only DFP
can initiate the VDM command to get partner identity information.
For a USBPD 3.0 UFP device, it may already get the identity information
from its port partner before DR_SWAP. If DR_SWAP send or receive at the
mean time, 'send_discover' flag will be raised again. It causes discover
identify action restart while entering ready state. And after all
discover actions are done, the 'tcpm_register_altmodes' will be called.
If old altmode is not unregistered, this sysfs create fail can be found.
In 'DR_SWAP_CHANGE_DR' state case, only DFP will unregister altmodes.
For UFP, the original altmodes keep registered.
This patch fix the logic that after DR_SWAP, 'tcpm_unregister_altmodes'
must be called whatever the current data role is.
Fixes: ae8a2ca8a221 ("usb: typec: Group all TCPCI/TCPM code together)
Reported-by: TommyYl Chen <tommyyl.chen@xxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: ChiYuan Huang <cy_huang@xxxxxxxxxxx>
---
Hi,
Below's the issue log for the reference.
*TCPM
[ 3.856679] AMS DISCOVER_MODES start
[ 3.856687] PD TX, header: 0x188f
[ 3.858827] PD TX complete, status: 0
[ 3.865330] PD RX, header: 0x2daf [1]
[ 3.865340] Rx VDM cmd 0xff01a043 type 1 cmd 3 len 2
[ 3.865348] AMS DISCOVER_MODES finished
[ 3.865352] Alternate mode 0: SVID 0xff01, VDO 1: 0x001c0045
[ 3.865362] AMS DISCOVER_MODES start
[ 3.865367] PD TX, header: 0x1a8f
[ 3.867802] PD TX complete, status: 0
[ 3.875208] PD RX, header: 0x2faf [1]
[ 3.875216] Rx VDM cmd 0x413ca043 type 1 cmd 3 len 2
[ 3.875222] AMS DISCOVER_MODES finished
[ 3.875225] Alternate mode 1: SVID 0x413c, VDO 1: 0x00000001
[ 3.938243] AMS GET_SINK_CAPABILITIES start
[ 3.938255] state change SNK_READY -> AMS_START [rev3 GET_SINK_CAPABILITIES]
[ 3.938266] state change AMS_START -> GET_SINK_CAP [rev3 GET_SINK_CAPABILITIES]
[ 3.938274] PD TX, header: 0xe88
[ 3.940268] PD TX complete, status: 0
[ 3.940310] pending state change GET_SINK_CAP -> GET_SINK_CAP_TIMEOUT @ 60 ms
[rev3 GET_SINK_CAPABILITIES]
[ 3.946291] PD RX, header: 0x13a4 [1]
[ 3.946295] Port partner FRS capable partner_frs_current:0 port_frs_current:0 enable:n
[ 3.946298] state change GET_SINK_CAP -> SNK_READY [rev3 GET_SINK_CAPABILITIES]
[ 3.946304] AMS GET_SINK_CAPABILITIES finished
[ 4.239342] CC1: 5 -> 4, CC2: 0 -> 0 [state SNK_READY, polarity 0, connected]
[ 4.256594] PD RX, header: 0x5a9 [1]
[ 4.256603] state change SNK_READY -> DR_SWAP_ACCEPT [rev3 DATA_ROLE_SWAP]
[ 4.256609] PD TX, header: 0x83
[ 4.258528] PD TX complete, status: 0
[ 4.258584] state change DR_SWAP_ACCEPT -> DR_SWAP_CHANGE_DR [rev3 DATA_ROLE_SWAP]
[ 4.258591] Requesting mux state 1, usb-role 1, orientation 1
[ 4.259588] AMS DATA_ROLE_SWAP finished
[ 4.259592] state change DR_SWAP_CHANGE_DR -> SNK_READY [rev3 NONE_AMS]
[ 4.259605] AMS DISCOVER_IDENTITY start
[ 4.259609] Sink TX No Go
[ 4.260874] CC1: 4 -> 5, CC2: 0 -> 0 [state SNK_READY, polarity 0, connected]
[ 4.359636] AMS DISCOVER_IDENTITY start
[ 4.359642] PD TX, header: 0x12af
[ 4.361884] PD TX complete, status: 0
[ 4.369433] PD RX, header: 0x578f [1]
[ 4.369439] Rx VDM cmd 0xff00a041 type 1 cmd 1 len 5
[ 4.369448] AMS DISCOVER_IDENTITY finished
[ 4.369515] Identity: 413c:c013.0712
[ 4.369521] AMS DISCOVER_SVIDS start
[ 4.369524] PD TX, header: 0x14af
[ 4.371696] PD TX complete, status: 0
[ 4.378564] PD RX, header: 0x398f [1]
[ 4.378573] Rx VDM cmd 0xff00a042 type 1 cmd 2 len 3
[ 4.378579] AMS DISCOVER_SVIDS finished
[ 4.378582] SVID 1: 0xff01
[ 4.378584] SVID 2: 0x413c
[ 4.378594] AMS DISCOVER_MODES start
[ 4.378597] PD TX, header: 0x16af
[ 4.380696] PD TX complete, status: 0
[ 4.387008] PD RX, header: 0x2b8f [1]
[ 4.387014] Rx VDM cmd 0xff01a043 type 1 cmd 3 len 2
[ 4.387021] AMS DISCOVER_MODES finished
[ 4.387023] Alternate mode 0: SVID 0xff01, VDO 1: 0x001c0045
[ 4.387029] AMS DISCOVER_MODES start
[ 4.387031] PD TX, header: 0x18af
[ 4.389134] PD TX complete, status: 0
[ 4.395528] PD RX, header: 0x2d8f [1]
[ 4.395538] Rx VDM cmd 0x413ca043 type 1 cmd 3 len 2
[ 4.395546] AMS DISCOVER_MODES finished
[ 4.395548] Alternate mode 1: SVID 0x413c, VDO 1: 0x00000001
*Kernel TRACE
sysfs: cannot create duplicate filename
'/devices/platform/soc/11d01000.i2c/i2c-0/0-0034/mt6360-tcpc.6.auto/typec/port0/port0.0/partner'
CPU: 2 PID: 299 Comm: mt6360-tcpc.6.a Tainted: GO 5.15.37-mtk+g880abc5122e7 #1
Hardware name: MediaTek MT8195 demo board (DT)
Call trace:
dump_backtrace+0x0/0x1ac
show_stack+0x24/0x30
dump_stack_lvl+0x68/0x84
dump_stack+0x1c/0x38
sysfs_warn_dup+0x70/0x90
typec_probe+0xa4/0x134 [typec]
really_probe.part.0+0xa4/0x310
__device_attach_driver+0x100/0x16c
bus_for_each_drv+0x84/0xe0
__device_attach+0xe0/0x1ac
device_add+0x39c/0x8b0
device_register+0x2c/0x40
typec_register_altmode+0x1f4/0x360 [typec]
typec_partner_register_altmode+0x1c/0x30 [typec]
tcpm_pd_rx_handler+0x19d4/0x1c0c [tcpm]
kthread_worker_fn+0xb8/0x290
kthread+0x15c/0x170
ret_from_fork+0x10/0x20
[ 4.395962] typec_displayport port0-partner.2: failed to create symlinks
[ 4.395967] typec_displayport: probe of port0-partner.2 failed with error -17
It seems it's a common issue if typec port supports the modal operation.
---
drivers/usb/typec/tcpm/tcpm.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c
index 904c7b4..59b366b 100644
--- a/drivers/usb/typec/tcpm/tcpm.c
+++ b/drivers/usb/typec/tcpm/tcpm.c
@@ -4594,14 +4594,13 @@ static void run_state_machine(struct tcpm_port *port)
tcpm_set_state(port, ready_state(port), 0);
break;
case DR_SWAP_CHANGE_DR:
- if (port->data_role == TYPEC_HOST) {
- tcpm_unregister_altmodes(port);
+ tcpm_unregister_altmodes(port);
+ if (port->data_role == TYPEC_HOST)
tcpm_set_roles(port, true, port->pwr_role,
TYPEC_DEVICE);
- } else {
+ else
tcpm_set_roles(port, true, port->pwr_role,
TYPEC_HOST);
- }
tcpm_ams_finish(port);
tcpm_set_state(port, ready_state(port), 0);
break;
Reviewed-by: Macpaul Lin <macpaul.lin@xxxxxxxxxxxx>
Thank for your help.
Regards,
Macpaul Lin