Hi Gerhard,
Today I added Your patches to 6.7-stable and moved back LTE modem to USB 3.0.
So, just waiting for… nothing or kernel panic. I’ll let you know.
> On 8 Jun 2020, at 19:13, Patrick Wildt <patr...@blueri.se> wrote:
>
> On Mon, Jun 08, 2020 at 05:31:44PM +0200, Gerhard Roth wrote:
>> On 2020-05-25 13:19, Martin Pieuchot wrote:
>>> On 25/05/20(Mon) 12:56, Gerhard Roth wrote:
>>>> On 5/22/20 9:05 PM, Mark Kettenis wrote:
>>>>>> From: Łukasz Lejtkowski <emig...@gmail.com>
>>>>>> Date: Fri, 22 May 2020 20:51:57 +0200
>>>>>>
>>>>>> Probably power supply 12 V is broken. Showing 16,87 V(Fluke 179) -
>>>>>> too high. Should be 12,25-12,50 V. I replaced to the new one.
>>>>>
>>>>> That might be why the device stops responding. The fact that cleaning
>>>>> up from a failed USB transaction leads to this panic is a bug though.
>>>>>
>>>>> And somebody just posted a very similar panic with ure(4). Something
>>>>> in the network stack is holding a mutex when it shouldn't.
>>>>
>>>> I think that holding the mutex is ok. The bug is calling the stop
>>>> routine in case of errors.
>>>>
>>>> This is what common foo_start() does:
>>>>
>>>> m_head = ifq_deq_begin(&ifp->if_snd);
>>>> if (foo_encap(sc, m_head, 0)) {
>>>> ifq_deq_rollback(&ifp->if_snd, m_head);
>>>> ...
>>>> return;
>>>> }
>>>> ifq_deq_commit(&ifp->if_snd, m_head);
>>>>
>>>> Here, ifq_deq_begin() grabs a mutex and it is held while
>>>> calling foo_encap().
>>>>
>>>> For USB network interfaces foo_encap() mostly does this:
>>>>
>>>> err = usbd_transfer(sc->sc_xfer);
>>>> if (err != USBD_IN_PROGRESS) {
>>>> foo_stop(sc);
>>>> return EIO;
>>>> }
>>>>
>>>> And foo_stop() calls usbd_abort_pipe() -> xhci_command_submit(),
>>>> which might sleep.
>>>>
>>>> How to fix? We could do the foo_encap() after the ifq_deq_commit(),
>>>> possibly dropping the current mbuf if encap fails (who cares
>>>> for the packets after foo_stop() anyway).
>>>
>>> That's the approach taken by drivers using ifq_dequeue(9) instead of
>>> ifq_deq_begin/commit().
>>>
>>>> Or change all the drivers to follow the path that if_aue.c takes:
>>>>
>>>> err = usbd_transfer(c->aue_xfer);
>>>> if (err != USBD_IN_PROGRESS) {
>>>> ...
>>>> /* Stop the interface from process context. */
>>>> usb_add_task(sc->aue_udev, &sc->aue_stop_task);
>>>> return (EIO);
>>>> }
>>>
>>> That's just trading the current problem for another one with higher
>>> complexity.
>>>
>>>> Any ideas, what's better? Or alternative proposals?
>>>
>>> Using ifq_dequeue(9) would have the advantage of unifying the code base.
>>> It introduces a behavior change. A simpler fix would be to call
>>> foo_stop() in the error path after ifq_deq_rollback().
>>>
>>
>> Hi,
>>
>> two weeks passed any nobody objected Martin's proposal. So I thought,
>> we could try to move on this way.
>>
>> Gerhard
>>
>
> From what I remember from various discussions, the goal should be to
> check if there's a buffer free in the ring, then dequeue and send, and
> it it can't be sent out, then drop it. With USB apparently those
> drivers "always" have an open buffer, so we can just dequeue and send,
> like you do in this diff. And if it gets dropped, that's fine.
>
> That said, I think IFQ_DEQUEUE() is old compat code, and we actually
> nowadays prefer:
>
> m_head = ifq_dequeue(&ifp->if_snd);
>
> If you look at the define for IFQ_DEQUEUE() you'll see it's marked
> as compat code. If you look at a new driver, like ixl(4), you'll
> see that it also uses ifq_dequeue().
>
> Sorry to to give you some work, but with that fixed: ok patrick@
>
> Patrick
>
>>
>> Index: sys/dev/usb/if_axe.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_axe.c,v
>> retrieving revision 1.139
>> diff -u -p -u -p -r1.139 if_axe.c
>> --- sys/dev/usb/if_axe.c 7 Jul 2019 06:40:10 -0000 1.139
>> +++ sys/dev/usb/if_axe.c 8 Jun 2020 15:13:25 -0000
>> @@ -1223,6 +1223,7 @@ axe_encap(struct axe_softc *sc, struct m
>> /* Transmit */
>> err = usbd_transfer(c->axe_xfer);
>> if (err != USBD_IN_PROGRESS) {
>> + c->axe_mbuf = NULL;
>> axe_stop(sc);
>> return(EIO);
>> }
>> @@ -1246,16 +1247,15 @@ axe_start(struct ifnet *ifp)
>> if (ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (axe_encap(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> /*
>> * If there's a BPF listener, bounce a copy of this frame
>> Index: sys/dev/usb/if_axen.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_axen.c,v
>> retrieving revision 1.27
>> diff -u -p -u -p -r1.27 if_axen.c
>> --- sys/dev/usb/if_axen.c 7 Jul 2019 06:40:10 -0000 1.27
>> +++ sys/dev/usb/if_axen.c 8 Jun 2020 14:49:26 -0000
>> @@ -1186,6 +1186,7 @@ axen_encap(struct axen_softc *sc, struct
>> /* Transmit */
>> err = usbd_transfer(c->axen_xfer);
>> if (err != USBD_IN_PROGRESS) {
>> + c->axen_mbuf = NULL;
>> axen_stop(sc);
>> return EIO;
>> }
>> @@ -1209,16 +1210,15 @@ axen_start(struct ifnet *ifp)
>> if (ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (axen_encap(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> /*
>> * If there's a BPF listener, bounce a copy of this frame
>> Index: sys/dev/usb/if_cdce.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_cdce.c,v
>> retrieving revision 1.76
>> diff -u -p -u -p -r1.76 if_cdce.c
>> --- sys/dev/usb/if_cdce.c 14 Nov 2019 13:50:55 -0000 1.76
>> +++ sys/dev/usb/if_cdce.c 8 Jun 2020 14:50:40 -0000
>> @@ -375,18 +375,16 @@ cdce_start(struct ifnet *ifp)
>> if (usbd_is_dying(sc->cdce_udev) || ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (cdce_encap(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>>
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>> -
>> #if NBPFILTER > 0
>> if (ifp->if_bpf)
>> bpf_mtap(ifp->if_bpf, m_head, BPF_DIRECTION_OUT);
>> @@ -422,6 +420,7 @@ cdce_encap(struct cdce_softc *sc, struct
>> 10000, cdce_txeof);
>> err = usbd_transfer(c->cdce_xfer);
>> if (err != USBD_IN_PROGRESS) {
>> + c->cdce_mbuf = NULL;
>> cdce_stop(sc);
>> return (EIO);
>> }
>> Index: sys/dev/usb/if_kue.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_kue.c,v
>> retrieving revision 1.89
>> diff -u -p -u -p -r1.89 if_kue.c
>> --- sys/dev/usb/if_kue.c 2 Oct 2018 19:49:10 -0000 1.89
>> +++ sys/dev/usb/if_kue.c 8 Jun 2020 14:52:27 -0000
>> @@ -829,6 +829,7 @@ kue_send(struct kue_softc *sc, struct mb
>> if (err != USBD_IN_PROGRESS) {
>> printf("%s: kue_send error=%s\n", sc->kue_dev.dv_xname,
>> usbd_errstr(err));
>> + c->kue_mbuf = NULL;
>> kue_stop(sc);
>> return (EIO);
>> }
>> @@ -852,17 +853,15 @@ kue_start(struct ifnet *ifp)
>> if (ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (kue_send(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> -
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> #if NBPFILTER > 0
>> /*
>> Index: sys/dev/usb/if_mos.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_mos.c,v
>> retrieving revision 1.40
>> diff -u -p -u -p -r1.40 if_mos.c
>> --- sys/dev/usb/if_mos.c 7 Jul 2019 06:40:10 -0000 1.40
>> +++ sys/dev/usb/if_mos.c 8 Jun 2020 15:15:42 -0000
>> @@ -1097,6 +1097,7 @@ mos_encap(struct mos_softc *sc, struct m
>> /* Transmit */
>> err = usbd_transfer(c->mos_xfer);
>> if (err != USBD_IN_PROGRESS) {
>> + c->mos_mbuf = NULL;
>> mos_stop(sc);
>> return(EIO);
>> }
>> @@ -1120,16 +1121,15 @@ mos_start(struct ifnet *ifp)
>> if (ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (mos_encap(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> /*
>> * If there's a BPF listener, bounce a copy of this frame
>> Index: sys/dev/usb/if_mue.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_mue.c,v
>> retrieving revision 1.7
>> diff -u -p -u -p -r1.7 if_mue.c
>> --- sys/dev/usb/if_mue.c 7 Jul 2019 06:40:10 -0000 1.7
>> +++ sys/dev/usb/if_mue.c 8 Jun 2020 14:55:07 -0000
>> @@ -987,6 +987,7 @@ mue_encap(struct mue_softc *sc, struct m
>> /* Transmit */
>> err = usbd_transfer(c->mue_xfer);
>> if (err != USBD_IN_PROGRESS) {
>> + c->mue_mbuf = NULL;
>> mue_stop(sc);
>> return(EIO);
>> }
>> @@ -1308,16 +1309,15 @@ mue_start(struct ifnet *ifp)
>> if (ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (mue_encap(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> /* If there's a BPF listener, bounce a copy of this frame to him. */
>> #if NBPFILTER > 0
>> Index: sys/dev/usb/if_smsc.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_smsc.c,v
>> retrieving revision 1.34
>> diff -u -p -u -p -r1.34 if_smsc.c
>> --- sys/dev/usb/if_smsc.c 8 Apr 2020 09:49:32 -0000 1.34
>> +++ sys/dev/usb/if_smsc.c 8 Jun 2020 15:02:20 -0000
>> @@ -649,16 +649,15 @@ smsc_start(struct ifnet *ifp)
>> return;
>> }
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (smsc_encap(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> #if NBPFILTER > 0
>> if (ifp->if_bpf)
>> @@ -1400,6 +1399,7 @@ smsc_encap(struct smsc_softc *sc, struct
>>
>> err = usbd_transfer(c->sc_xfer);
>> if (err != USBD_IN_PROGRESS) {
>> + c->sc_mbuf = NULL;
>> smsc_stop(sc);
>> return (EIO);
>> }
>> Index: sys/dev/usb/if_ugl.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_ugl.c,v
>> retrieving revision 1.23
>> diff -u -p -u -p -r1.23 if_ugl.c
>> --- sys/dev/usb/if_ugl.c 2 Oct 2018 19:49:10 -0000 1.23
>> +++ sys/dev/usb/if_ugl.c 8 Jun 2020 15:16:09 -0000
>> @@ -566,6 +566,7 @@ ugl_send(struct ugl_softc *sc, struct mb
>> if (err != USBD_IN_PROGRESS) {
>> printf("%s: ugl_send error=%s\n", sc->sc_dev.dv_xname,
>> usbd_errstr(err));
>> + c->ugl_mbuf = NULL;
>> ugl_stop(sc);
>> return (EIO);
>> }
>> @@ -589,17 +590,15 @@ ugl_start(struct ifnet *ifp)
>> if (ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (ugl_send(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> -
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> #if NBPFILTER > 0
>> /*
>> Index: sys/dev/usb/if_upl.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_upl.c,v
>> retrieving revision 1.75
>> diff -u -p -u -p -r1.75 if_upl.c
>> --- sys/dev/usb/if_upl.c 2 Oct 2018 19:49:10 -0000 1.75
>> +++ sys/dev/usb/if_upl.c 8 Jun 2020 15:06:43 -0000
>> @@ -546,6 +546,7 @@ upl_send(struct upl_softc *sc, struct mb
>> if (err != USBD_IN_PROGRESS) {
>> printf("%s: upl_send error=%s\n", sc->sc_dev.dv_xname,
>> usbd_errstr(err));
>> + c->upl_mbuf = NULL;
>> upl_stop(sc);
>> return (EIO);
>> }
>> @@ -569,17 +570,15 @@ upl_start(struct ifnet *ifp)
>> if (ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (upl_send(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> -
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> #if NBPFILTER > 0
>> /*
>> Index: sys/dev/usb/if_ure.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_ure.c,v
>> retrieving revision 1.14
>> diff -u -p -u -p -r1.14 if_ure.c
>> --- sys/dev/usb/if_ure.c 10 Mar 2020 01:11:30 -0000 1.14
>> +++ sys/dev/usb/if_ure.c 8 Jun 2020 15:12:53 -0000
>> @@ -775,16 +775,15 @@ ure_start(struct ifnet *ifp)
>> break;
>> }
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> break;
>>
>> if (ure_encap(sc, m_head)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> break;
>> }
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> #if NBPFILTER > 0
>> if (ifp->if_bpf)
>> @@ -1933,6 +1932,7 @@ ure_encap(struct ure_softc *sc, struct m
>>
>> err = usbd_transfer(c->uc_xfer);
>> if (err != 0 && err != USBD_IN_PROGRESS) {
>> + c->uc_mbuf = NULL;
>> ure_stop(sc);
>> return (EIO);
>> }
>> Index: sys/dev/usb/if_urndis.c
>> ===================================================================
>> RCS file: /cvs/src/sys/dev/usb/if_urndis.c,v
>> retrieving revision 1.69
>> diff -u -p -u -p -r1.69 if_urndis.c
>> --- sys/dev/usb/if_urndis.c 22 Jan 2019 18:06:05 -0000 1.69
>> +++ sys/dev/usb/if_urndis.c 8 Jun 2020 15:14:57 -0000
>> @@ -804,6 +804,7 @@ urndis_encap(struct urndis_softc *sc, st
>> /* Transmit */
>> err = usbd_transfer(c->sc_xfer);
>> if (err != USBD_IN_PROGRESS) {
>> + c->sc_mbuf = NULL;
>> urndis_stop(sc);
>> return(EIO);
>> }
>> @@ -1190,16 +1191,15 @@ urndis_start(struct ifnet *ifp)
>> if (usbd_is_dying(sc->sc_udev) || ifq_is_oactive(&ifp->if_snd))
>> return;
>>
>> - m_head = ifq_deq_begin(&ifp->if_snd);
>> + IFQ_DEQUEUE(&ifp->if_snd, m_head);
>> if (m_head == NULL)
>> return;
>>
>> if (urndis_encap(sc, m_head, 0)) {
>> - ifq_deq_rollback(&ifp->if_snd, m_head);
>> + m_freem(m_head);
>> ifq_set_oactive(&ifp->if_snd);
>> return;
>> }
>> - ifq_deq_commit(&ifp->if_snd, m_head);
>>
>> /*
>> * If there's a BPF listener, bounce a copy of this frame
