Re: ttyACM and BREAK chars ?
Am Donnerstag, den 12.09.2019, 07:09 + schrieb Joakim Tjernlund: > On Wed, 2019-09-11 at 20:27 +0200, Oliver Neukum wrote: > > Am Mittwoch, den 11.09.2019, 14:34 + schrieb Joakim Tjernlund: > > > On Wed, 2019-09-11 at 16:22 +0200, Oliver Neukum wrote: > > > > CAUTION: This email originated from outside of the organization. Do not > > > > click links or open attachments unless you recognize the sender and > > > > know the content is safe. > > > > > > > > > > > > Am Mittwoch, den 11.09.2019, 12:39 + schrieb Joakim Tjernlund: > > > > > Every now and then my ttyACM0 hangs up or sends a BREAK char to my > > > > > device. > > > > > I am trying to make ttyACM ignore incoming(over USB) and not emit > > > > > any BREAK automatically using termios (IGN_BRK) but that does not > > > > > make a difference. > > > > > > > > > > Is BREAK handling unimpl. in ttyACM ? > > > > > > > > acm_send_break() implements it. > > > > > > Yes, I se that funktion but I don't see how one can ignore received BREAKs > > > If I set IGN_BRK on /dev/ttyACM0 I expect that every BREAK should just be > > > ignored > > > > Handling breaks looks a bit broken on CDC-ACM. > > Could you test the attached patch? > > > > Sure, I can test it but from looking at the patch it seems like ACM already > ignores > BREAKs(hardcoded) and with your patch you actually start reporting them. Well, what is not reported cannot really be ignored. AFAICT n_tty_receive_break() should solve the issue generically. > My problem is sudden disconnects I cannot explain but I think they are > connect to BREAKs > I have seen these errors in dmesg though, not sure if they help the diagnose: > [181780.167987] usb usb1-port6: disabled by hub (EMI?), re-enabling... The relevant fault happens likely just before that. > [181780.168208] cdc_acm 1-6.3:1.1: acm_ctrl_irq - usb_submit_urb failed: -19 > [181780.167996] usb 1-6: USB disconnect, device number 30 > [181780.176548] usb 1-6-port2: attempt power cycle > [181781.772847] usb 1-6.3: USB disconnect, device number 32 > [181781.773134] cdc_acm 1-6.3:1.1: failed to set dtr/rts Either your cabling is indeed crap, or something crashes your device. Regards Oliver
Re: ttyACM and BREAK chars ?
On Wed, 2019-09-11 at 20:27 +0200, Oliver Neukum wrote: > Am Mittwoch, den 11.09.2019, 14:34 + schrieb Joakim Tjernlund: > > On Wed, 2019-09-11 at 16:22 +0200, Oliver Neukum wrote: > > > CAUTION: This email originated from outside of the organization. Do not > > > click links or open attachments unless you recognize the sender and know > > > the content is safe. > > > > > > > > > Am Mittwoch, den 11.09.2019, 12:39 + schrieb Joakim Tjernlund: > > > > Every now and then my ttyACM0 hangs up or sends a BREAK char to my > > > > device. > > > > I am trying to make ttyACM ignore incoming(over USB) and not emit > > > > any BREAK automatically using termios (IGN_BRK) but that does not make > > > > a difference. > > > > > > > > Is BREAK handling unimpl. in ttyACM ? > > > > > > acm_send_break() implements it. > > > > Yes, I se that funktion but I don't see how one can ignore received BREAKs > > If I set IGN_BRK on /dev/ttyACM0 I expect that every BREAK should just be > > ignored > > Handling breaks looks a bit broken on CDC-ACM. > Could you test the attached patch? > Sure, I can test it but from looking at the patch it seems like ACM already ignores BREAKs(hardcoded) and with your patch you actually start reporting them. My problem is sudden disconnects I cannot explain but I think they are connect to BREAKs I have seen these errors in dmesg though, not sure if they help the diagnose: [181780.167987] usb usb1-port6: disabled by hub (EMI?), re-enabling... [181780.168208] cdc_acm 1-6.3:1.1: acm_ctrl_irq - usb_submit_urb failed: -19 [181780.167996] usb 1-6: USB disconnect, device number 30 [181780.176548] usb 1-6-port2: attempt power cycle [181781.772847] usb 1-6.3: USB disconnect, device number 32 [181781.773134] cdc_acm 1-6.3:1.1: failed to set dtr/rts
Re: ttyACM and BREAK chars ?
Am Mittwoch, den 11.09.2019, 14:34 + schrieb Joakim Tjernlund:
> On Wed, 2019-09-11 at 16:22 +0200, Oliver Neukum wrote:
> > CAUTION: This email originated from outside of the organization. Do not
> > click links or open attachments unless you recognize the sender and know
> > the content is safe.
> >
> >
> > Am Mittwoch, den 11.09.2019, 12:39 + schrieb Joakim Tjernlund:
> > > Every now and then my ttyACM0 hangs up or sends a BREAK char to my device.
> > > I am trying to make ttyACM ignore incoming(over USB) and not emit
> > > any BREAK automatically using termios (IGN_BRK) but that does not make a
> > > difference.
> > >
> > > Is BREAK handling unimpl. in ttyACM ?
> >
> > acm_send_break() implements it.
>
> Yes, I se that funktion but I don't see how one can ignore received BREAKs
> If I set IGN_BRK on /dev/ttyACM0 I expect that every BREAK should just be
> ignored
Handling breaks looks a bit broken on CDC-ACM.
Could you test the attached patch?
Regards
Oliver
From 74a16a0fdc056659b0543ec377b51fa231a423c2 Mon Sep 17 00:00:00 2001
From: Oliver Neukum
Date: Wed, 11 Sep 2019 20:17:38 +0200
Subject: [PATCH] cdc-acm: fix BREAK rx code path adding necessary calls
Counting break events is nice but we should actually report them to
the tty layer.
Fixes: 5a6a62bdb9257 ("cdc-acm: add TIOCMIWAIT")
Signed-off-by: Oliver Neukum
---
drivers/usb/class/cdc-acm.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c
index 62f4fb9b362f..89d97d9763b0 100644
--- a/drivers/usb/class/cdc-acm.c
+++ b/drivers/usb/class/cdc-acm.c
@@ -312,8 +312,10 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
acm->iocount.dsr++;
if (difference & ACM_CTRL_DCD)
acm->iocount.dcd++;
- if (newctrl & ACM_CTRL_BRK)
+ if (newctrl & ACM_CTRL_BRK) {
acm->iocount.brk++;
+ tty_insert_flip_char(&acm->port, 0, TTY_BREAK);
+ }
if (newctrl & ACM_CTRL_RI)
acm->iocount.rng++;
if (newctrl & ACM_CTRL_FRAMING)
--
2.16.4
Re: ttyACM and BREAK chars ?
On Wed, 2019-09-11 at 16:22 +0200, Oliver Neukum wrote: > CAUTION: This email originated from outside of the organization. Do not click > links or open attachments unless you recognize the sender and know the > content is safe. > > > Am Mittwoch, den 11.09.2019, 12:39 + schrieb Joakim Tjernlund: > > Every now and then my ttyACM0 hangs up or sends a BREAK char to my device. > > I am trying to make ttyACM ignore incoming(over USB) and not emit > > any BREAK automatically using termios (IGN_BRK) but that does not make a > > difference. > > > > Is BREAK handling unimpl. in ttyACM ? > > acm_send_break() implements it. Yes, I se that funktion but I don't see how one can ignore received BREAKs If I set IGN_BRK on /dev/ttyACM0 I expect that every BREAK should just be ignored > But the support is optional in ACM devices. > > What is bmCapabilities in sysfs for your device? I found one bmCapabilities in sysfs: cat /sys/devices/pci:00/:00:14.0/usb1/1-6/1-6.3/1-6.3:1.1/bmCapabilities 2 Locks like my device Jocke
Re: ttyACM and BREAK chars ?
Am Mittwoch, den 11.09.2019, 12:39 + schrieb Joakim Tjernlund: > Every now and then my ttyACM0 hangs up or sends a BREAK char to my device. > I am trying to make ttyACM ignore incoming(over USB) and not emit > any BREAK automatically using termios (IGN_BRK) but that does not make a > difference. > > Is BREAK handling unimpl. in ttyACM ? acm_send_break() implements it. But the support is optional in ACM devices. What is bmCapabilities in sysfs for your device? Regards Oliver
