Hi, The "BUG! echo_skb is occupied" msg is printed when the network tx queue is restarted, while there is no room left in the echo_skb array. Note that this msg does not prevent any CAN frame to be written on the bus. There's actually one place where the network tx queue is restarted, however the echo_skb array is filled: (see https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/can/peak_canfd/peak_pciefd_main.c#n353) A driver version in which the below patch has been applied /* handle tx link interrupt (if any) */ if (pciefd_irq_is_lnk(priv->irq_status)) { unsigned long flags; spin_lock_irqsave(&priv->tx_lock, flags); priv->tx_pages_free++; spin_unlock_irqrestore(&priv->tx_lock, flags); - - /* wake producer up */ - netif_wake_queue(priv->ucan.ndev); } has run during the whole weekend (~60 h). The echo_skb array size has also been reduced to 8 slots (instead of 24), to increase the probability for the issue to occur; two "cangen -g 0 -i" were running on can0 and can1. Unfortunately, during this period, the "BUG! echo is occupied" msg has been still sporadically printed (4 times, 2 times for can0, 2 times for can1). Still under investigation... Regards, > -----Original Message----- > From: Diana Burgess <diana@xxxxxxxxxxxxxxxx> > Sent: samedi 3 mars 2018 02:38 > To: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> > Cc: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>; Stéphane Grosjean > <s.grosjean@xxxxxxxxxxxxxxx>; Philipp Schrader <philipp@peloton- > tech.com>; linux-can@xxxxxxxxxxxxxxx; linux-rt-users@xxxxxxxxxxxxxxx > Subject: Re: peak_pciefd 0000:06:00.0 can1: can_put_echo_skb: BUG! > echo_skb is occupied! > > On Tue, Feb 27, 2018 at 12:58 AM, Sebastian Andrzej Siewior > <bigeasy@xxxxxxxxxxxxx> wrote: > > On 2018-02-26 11:55:11 [-0800], Diana Burgess wrote: > >> That patch is part of my branch already so it does not fix this bug. > >> > >> Also 4.15 is not part of rt-devel yet so I did not try to build and > >> run that version. > > about that. The tree you were using is not updated (is EOL) so I > > suggest to upgrade to 4.14-RT. This may not fix your bug but you get a > > kernel with stable/security updates. > > > > You mentioned that you use -RT and you see this problem only with the > > peak card. You never mentioned if this also happens often or rarely or > > if this happens once you disable RT and you keep doing what you are > > doing. > > > >> > >> Thanks, > >> > > > > Sebastian > > I've upgraded to 4.14-RT and tried with and without RT. Using RT I see the > bug approximately every 45s (though it is not consistent). This time between > bugs increases when not using RT, but does not go away. > > -- > Diana Burgess -- PEAK-System Technik GmbH Sitz der Gesellschaft Darmstadt - HRB 9183 Geschaeftsfuehrung: Alexander Gach / Uwe Wilhelm -- ��.n��������+%������w��{.n�����{�����ǫ���ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
