Messages in this thread | | | Date | Fri, 29 Mar 2024 18:21:08 +0200 | From | Dmitry Baryshkov <> | Subject | Re: [PATCH 2/5] usb: typec: ucsi: Check for notifications after init |
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On Wed, Mar 20, 2024 at 08:39:23AM +0100, Christian A. Ehrhardt wrote: > The completion notification for the final SET_NOTIFICATION_ENABLE > command during initialization can include a connector change > notification. However, at the time this completion notification is > processed, the ucsi struct is not ready to handle this notification. > As a result the notification is ignored and the controller > never sends an interrupt again. > > Re-check CCI for a pending connector state change after > initialization is complete. Adjust the corresponding debug > message accordingly. > > Fixes: 71a1fa0df2a3 ("usb: typec: ucsi: Store the notification mask") > Cc: stable@vger.kernel.org > Signed-off-by: Christian A. Ehrhardt <lk@c--e.de> > --- > drivers/usb/typec/ucsi/ucsi.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c > index 8a6645ffd938..dceeed207569 100644 > --- a/drivers/usb/typec/ucsi/ucsi.c > +++ b/drivers/usb/typec/ucsi/ucsi.c > @@ -1237,7 +1237,7 @@ void ucsi_connector_change(struct ucsi *ucsi, u8 num) > struct ucsi_connector *con = &ucsi->connector[num - 1]; > > if (!(ucsi->ntfy & UCSI_ENABLE_NTFY_CONNECTOR_CHANGE)) { > - dev_dbg(ucsi->dev, "Bogus connector change event\n"); > + dev_dbg(ucsi->dev, "Early connector change event\n"); > return; > } > > @@ -1636,6 +1636,7 @@ static int ucsi_init(struct ucsi *ucsi) > { > struct ucsi_connector *con, *connector; > u64 command, ntfy; > + u32 cci; > int ret; > int i; > > @@ -1688,6 +1689,13 @@ static int ucsi_init(struct ucsi *ucsi) > > ucsi->connector = connector; > ucsi->ntfy = ntfy; > + > + ret = ucsi->ops->read(ucsi, UCSI_CCI, &cci, sizeof(cci)); > + if (ret) > + return ret; > + if (UCSI_CCI_CONNECTOR(READ_ONCE(cci))) > + ucsi_connector_change(ucsi, cci); > +
I think this leaves place for the race. With this patchset + "Ack connector change early" in place Neil triggered the following backtrace on sm8550 HDK while testing my UCSI-qcom-fixes patchset: What happens:
[ 10.421640] write: 00000000: 05 00 e7 db 00 00 00 00
SET_NOTIFICATION_ENABLE
[ 10.432359] read: 00000000: 10 01 00 00 00 00 00 80 00 00 00 00 00 00 00 00 [ 10.469553] read: 00000010: 04 58 29 20 00 00 00 00 00 00 00 00 00 03 30 01 [ 10.476783] read: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 10.489552] notify: 00000000: 00 00 00 80
COMMAND_COMPLETE
[ 10.494194] read: 00000000: 10 01 00 00 00 00 00 80 00 00 00 00 00 00 00 00 [ 10.501370] read: 00000010: 04 58 29 20 00 00 00 00 00 00 00 00 00 03 30 01 [ 10.508578] read: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 10.515757] write: 00000000: 04 00 02 00 00 00 00 00
ACK_CC_CI(command completed)
[ 10.521100] read: 00000000: 10 01 00 00 00 00 00 20 00 00 00 00 00 00 00 00 [ 10.528363] read: 00000010: 04 58 29 20 00 00 00 00 00 00 00 00 00 03 30 01 [ 10.535603] read: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [ 10.549549] notify: 00000000: 00 00 00 20
ACK_COMPLETE
[Here ucsi->connector and ucsi->ntfy are being set by ucsi_init()
[ 10.566654] read: 00000010: 04 58 29 20 00 00 00 00 00 00 00 00 00 03 30 01 [ 10.593553] notify: 00000000: 02 00 00 20
Event with CONNECTION_CHANGE. It also schedules connector_change work, because ucsi->ntfy is already set
[ 10.595796] read: 00000000: 10 01 00 00 02 00 00 20 00 00 00 00 00 00 00 00 [ 10.595798] read: 00000010: 04 58 29 20 00 00 00 00 00 00 00 00 00 03 30 01 [ 10.595799] read: 00000020: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
The CCI read coming from ucsi_init()
[ 10.595807] ------------[ cut here ]------------ [ 10.595808] WARNING: CPU: 6 PID: 101 at kernel/workqueue.c:2384 __queue_work+0x374/0x474
[skipped the register dump]
[ 10.595953] __queue_work+0x374/0x474 [ 10.595956] queue_work_on+0x68/0x84 [ 10.595959] ucsi_connector_change+0x54/0x88 [typec_ucsi] [ 10.595963] ucsi_init_work+0x834/0x85c [typec_ucsi] [ 10.595968] process_one_work+0x148/0x29c [ 10.595971] worker_thread+0x2fc/0x40c [ 10.595974] kthread+0x110/0x114 [ 10.595978] ret_from_fork+0x10/0x20 [ 10.595985] ---[ end trace 0000000000000000 ]---
Warning, because the work is already scheduled.
> return 0; > > err_unregister: > -- > 2.40.1 >
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