Re: Fast HDLC driver

Re: Fast HDLC driver

[Owen Green]

You can find it on:

http://www.qslinux.com/

I`ve posted the .c file in the list too...

Owen.

--- Der Herr Hofrat <der.herr@mail.hofr.at> wrote:
> >
> > Hi all,
> >
> > I`ve started working on a new project were a high
> > performace hdlc channel is needed (at least 4Mbps
> on
> > MPC8xx-50Mhz).
> > I found several drivers for hdlc, but some are not
> > very fast (copies memory,... ), most of them calls
> > netif_rx from inside interrupt_handler (I don`t
> think
> > this is the best place for doing that, watchdog
> may
> > expire if the interface gets very busy..).
> > The only driver I found that seems to be really
> fast
> > and doesnt do all this stuff in interrupt context
> is
> > for kernel-2.2 (QSLINUX).
>
> do you have a URL to that driver ??
>
> thx !
> hofrat


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linuxppc_2_4_devel, rc1 and rc2 problem.

[Joakim Tjernlund]

I upgraded my linuxppc_2_4_devel from pre8(1.1130) to rc1(1.1157) and noticed that
may syslog had problems to start:

NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
VFS: Mounted root (jffs2 filesystem).
Freeing unused kernel memory: 64k init
INIT: version 2.78 booting
Fast boot, no file system check
none on /dev/shm type shm (rw)
ramfs on /tmp type ramfs (rw)
ramfs on /var/run type ramfs (rw)
ramfs on /tftpboot/log type ramfs (rw)
Cleaning: /etc/network/ifstate.
Enabling packet forwarding: done.
Disable TCP/IP Explicit Congestion Notification: done.
Configuring network interfaces: done.
Cleaning: /tmp /var/lock /var/run.
INIT: Entering runlevel: 2
Starting system log daemon: syslogd/etc/rc.d/rc2.d/S10syslog: line 53:    50 Ter
minated              start-stop-daemon -v --start --quiet --exec /sbin/syslogd -
- $SYSLOGD
 klogd.
Starting internet superserver: inetd.

I then tried rc2(BK curr) and got the same problem. I am running a custom mpc860 board.

Anyone else noticed this?

   Jocke

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Re: linuxppc_2_4_devel, rc1 and rc2 problem.

[Tom Rini]

On Wed, Nov 20, 2002 at 12:55:01PM +0100, Joakim Tjernlund wrote:
>

> I upgraded my linuxppc_2_4_devel from pre8(1.1130) to rc1(1.1157) and noticed that
> may syslog had problems to start:
>
[snip]

> I then tried rc2(BK curr) and got the same problem. I am running a custom mpc860 board.
>
> Anyone else noticed this?

I haven't tried yet.  Have you tried 'porting' your custom board to
vanilla 2.4.x, which would make it easier to see which, if any of these
upsteram revisions introduced a problem?  The only 8xx-specific changes
in that time have been your i2c changes and a serial fixup.

--
Tom Rini (TR1265)
http://gate.crashing.org/~trini/

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RE: linuxppc_2_4_devel, rc1 and rc2 problem.

[Joakim Tjernlund]

>
> On Wed, Nov 20, 2002 at 12:55:01PM +0100, Joakim Tjernlund wrote:
> >
>
> > I upgraded my linuxppc_2_4_devel from pre8(1.1130) to rc1(1.1157) and noticed that
> > may syslog had problems to start:
> >
> [snip]
>
> > I then tried rc2(BK curr) and got the same problem. I am running a custom mpc860 board.
> >
> > Anyone else noticed this?
>
> I haven't tried yet.  Have you tried 'porting' your custom board to
> vanilla 2.4.x, which would make it easier to see which, if any of these
> upsteram revisions introduced a problem?  The only 8xx-specific changes
> in that time have been your i2c changes and a serial fixup.

hmm, my i2c stuff got into rc2 (and uart too?). I see this on rc2 AND rc1, but NOT in pre8.
No, I have not tried to port it to vanilla 2.4.x. It requires some work to do that.

 Jocke
>
> --
> Tom Rini (TR1265)
> http://gate.crashing.org/~trini/
>


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Re: linuxppc_2_4_devel, rc1 and rc2 problem.

[Tom Rini]

On Wed, Nov 20, 2002 at 04:46:05PM +0100, Joakim Tjernlund wrote:
>
> >
> > On Wed, Nov 20, 2002 at 12:55:01PM +0100, Joakim Tjernlund wrote:
> > >
> >
> > > I upgraded my linuxppc_2_4_devel from pre8(1.1130) to rc1(1.1157) and noticed that
> > > may syslog had problems to start:
> > >
> > [snip]
> >
> > > I then tried rc2(BK curr) and got the same problem. I am running a custom mpc860 board.
> > >
> > > Anyone else noticed this?
> >
> > I haven't tried yet.  Have you tried 'porting' your custom board to
> > vanilla 2.4.x, which would make it easier to see which, if any of these
> > upsteram revisions introduced a problem?  The only 8xx-specific changes
> > in that time have been your i2c changes and a serial fixup.
>
> hmm, my i2c stuff got into rc2 (and uart too?). I see this on rc2 AND rc1, but NOT in pre8.
> No, I have not tried to port it to vanilla 2.4.x. It requires some work to do that.

They both made it in post rc1 I think, yes.  Try going back carefully
via bk changes and bk export -tr1.xxxxx (find when
/home/.../linuxppc_2_4 was merged into /home/.../linuxppc_2_4_devel).

--
Tom Rini (TR1265)
http://gate.crashing.org/~trini/

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RE: linuxppc_2_4_devel, rc1 and rc2 problem.

[Joakim Tjernlund]

> >
> > hmm, my i2c stuff got into rc2 (and uart too?). I see this on rc2 AND rc1, but NOT in pre8.
> > No, I have not tried to port it to vanilla 2.4.x. It requires some work to do that.
>
> They both made it in post rc1 I think, yes.  Try going back carefully
> via bk changes and bk export -tr1.xxxxx (find when
> /home/.../linuxppc_2_4 was merged into /home/.../linuxppc_2_4_devel).

The error ocurres between changeset 1.1130 - 1.1137.
I forgot to mention that the error only happens on a 862,100Mhz, 16KB icache, 8KB dcache.
My 860,80Mz does not show the problem.

Idea's ?

  Jocke


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Re: linuxppc_2_4_devel, rc1 and rc2 problem.

[Tom Rini]

On Wed, Nov 20, 2002 at 07:55:35PM +0100, Joakim Tjernlund wrote:
>
> > >
> > > hmm, my i2c stuff got into rc2 (and uart too?). I see this on rc2 AND rc1, but NOT in pre8.
> > > No, I have not tried to port it to vanilla 2.4.x. It requires some work to do that.
> >
> > They both made it in post rc1 I think, yes.  Try going back carefully
> > via bk changes and bk export -tr1.xxxxx (find when
> > /home/.../linuxppc_2_4 was merged into /home/.../linuxppc_2_4_devel).
>
> The error ocurres between changeset 1.1130 - 1.1137.
> I forgot to mention that the error only happens on a 862,100Mhz, 16KB icache, 8KB dcache.
> My 860,80Mz does not show the problem.
>
> Idea's ?

Can you narrow down the ChangeSet it occured at a bit?

--
Tom Rini (TR1265)
http://gate.crashing.org/~trini/

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RE: linuxppc_2_4_devel, rc1 and rc2 problem.

[Joakim Tjernlund]

> On Wed, Nov 20, 2002 at 07:55:35PM +0100, Joakim Tjernlund wrote:
> >
> > > >
> > > > hmm, my i2c stuff got into rc2 (and uart too?). I see this on rc2 AND rc1, but NOT in pre8.
> > > > No, I have not tried to port it to vanilla 2.4.x. It requires some work to do that.
> > >
> > > They both made it in post rc1 I think, yes.  Try going back carefully
> > > via bk changes and bk export -tr1.xxxxx (find when
> > > /home/.../linuxppc_2_4 was merged into /home/.../linuxppc_2_4_devel).
> >
> > The error ocurres between changeset 1.1130 - 1.1137.
> > I forgot to mention that the error only happens on a 862,100Mhz, 16KB icache, 8KB dcache.
> > My 860,80Mz does not show the problem.
> >
> > Idea's ?
>
> Can you narrow down the ChangeSet it occured at a bit?

Aaargh, now I am getting it in pre8 as well. However I have made
some progress:

I have 2 custom boards one mpc862(100Mhz, 16KB icache, 8KB dcache) and a
mpc860(80Mz,4KB icache, 4KB dcache). If I overclock the mpc860 to 100MHz I get
the same problem. If I set the clock on both boards to 95MHz all is well. If I overclock
the mpc862 to 105 MHz it works fine.

It turns out that syslog is actually running after the error. If I stop syslog and
start it again it works fine. If adjust my script so klogd is started before
syslogd all is well to.

This looks like a race somewhere to me, but i have no clue as to where.

Anyone?

    Jocke


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RE: linuxppc_2_4_devel, rc1 and rc2 problem.

[Joakim Tjernlund]

Sending this to the embedded list as well.

 Jocke
> On Wed, Nov 20, 2002 at 07:55:35PM +0100, Joakim Tjernlund wrote:
> >
> > > >
> > > > hmm, my i2c stuff got into rc2 (and uart too?). I see this on rc2 AND rc1, but NOT in pre8.
> > > > No, I have not tried to port it to vanilla 2.4.x. It requires some work to do that.
> > >
> > > They both made it in post rc1 I think, yes.  Try going back carefully
> > > via bk changes and bk export -tr1.xxxxx (find when
> > > /home/.../linuxppc_2_4 was merged into /home/.../linuxppc_2_4_devel).
> >
> > The error ocurres between changeset 1.1130 - 1.1137.
> > I forgot to mention that the error only happens on a 862,100Mhz, 16KB icache, 8KB dcache.
> > My 860,80Mz does not show the problem.
> >
> > Idea's ?
>
> Can you narrow down the ChangeSet it occured at a bit?

Aaargh, now I am getting it in pre8 as well. However I have made
some progress:

I have 2 custom boards one mpc862(100Mhz, 16KB icache, 8KB dcache) and a
mpc860(80Mz,4KB icache, 4KB dcache). If I overclock the mpc860 to 100MHz I get
the same problem. If I set the clock on both boards to 95MHz all is well. If I overclock
the mpc862 to 105 MHz it works fine.

It turns out that syslog is actually running after the error. If I stop syslog and
start it again it works fine. If adjust my script so klogd is started before
syslogd all is well to.

This looks like a race somewhere to me, but i have no clue as to where.

Anyone?

    Jocke


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RE: linuxppc_2_4_devel, rc1 and rc2 problem.

[Joakim Tjernlund]

>
> Sending this to the embedded list as well.
>
>  Jocke
> > On Wed, Nov 20, 2002 at 07:55:35PM +0100, Joakim Tjernlund wrote:
> > >
> > > > >
> > > > > hmm, my i2c stuff got into rc2 (and uart too?). I see this on rc2 AND rc1, but NOT in pre8.
> > > > > No, I have not tried to port it to vanilla 2.4.x. It requires some work to do that.
> > > >
> > > > They both made it in post rc1 I think, yes.  Try going back carefully
> > > > via bk changes and bk export -tr1.xxxxx (find when
> > > > /home/.../linuxppc_2_4 was merged into /home/.../linuxppc_2_4_devel).
> > >
> > > The error ocurres between changeset 1.1130 - 1.1137.
> > > I forgot to mention that the error only happens on a 862,100Mhz, 16KB icache, 8KB dcache.
> > > My 860,80Mz does not show the problem.
> > >
> > > Idea's ?
> >
> > Can you narrow down the ChangeSet it occured at a bit?
>
> Aaargh, now I am getting it in pre8 as well. However I have made
> some progress:
>
> I have 2 custom boards one mpc862(100Mhz, 16KB icache, 8KB dcache) and a
> mpc860(80Mz,4KB icache, 4KB dcache). If I overclock the mpc860 to 100MHz I get
> the same problem. If I set the clock on both boards to 95MHz all is well. If I overclock
> the mpc862 to 105 MHz it works fine.
>
> It turns out that syslog is actually running after the error. If I stop syslog and
> start it again it works fine. If adjust my script so klogd is started before
> syslogd all is well to.
>
> This looks like a race somewhere to me, but i have no clue as to where.
>
> Anyone?
>
>     Jocke

hmm, if I upgrade the JFFS2 filesystem to CVS HEAD, the problem goes away.

   Jocke


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Re: linuxppc_2_4_devel, rc1 and rc2 problem.

[David Woodhouse]

joakim.tjernlund@lumentis.se said:
> Sending this to the embedded list as well.

-ENOCONTEXT.

--
dwmw2


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RE: linuxppc_2_4_devel, rc1 and rc2 problem.

[Joakim Tjernlund]

>
> -ENOCONTEXT.
:-), sorry the context was lost due to me beeing a moron.

Anyway here is the problem again:

I upgraded my linuxppc_2_4_devel from pre8(1.1130) to rc1(1.1157) and noticed that
my syslog had problems to start:

NET4: Unix domain sockets 1.0/SMP for Linux NET4.0.
VFS: Mounted root (jffs2 filesystem).
Freeing unused kernel memory: 64k init
INIT: version 2.78 booting
Fast boot, no file system check
none on /dev/shm type shm (rw)
ramfs on /tmp type ramfs (rw)
ramfs on /var/run type ramfs (rw)
ramfs on /tftpboot/log type ramfs (rw)
Cleaning: /etc/network/ifstate.
Enabling packet forwarding: done.
Disable TCP/IP Explicit Congestion Notification: done.
Configuring network interfaces: done.
Cleaning: /tmp /var/lock /var/run.
INIT: Entering runlevel: 2
Starting system log daemon: syslogd/etc/rc.d/rc2.d/S10syslog: line 53:    50 Ter
minated              start-stop-daemon -v --start --quiet --exec /sbin/syslogd -
- $SYSLOGD
 klogd.
Starting internet superserver: inetd.

I then started to backout the changes between pre8 and rc1 to see where the problem was.
That gave me:

>> Aaargh, now I am getting it in pre8 as well. However I have made
>> some progress:
>>
>> I have 2 custom boards one mpc862(100Mhz, 16KB icache, 8KB dcache) and a
>> mpc860(80Mz,4KB icache, 4KB dcache). If I overclock the mpc860 to 100MHz I get
>> the same problem. If I set the clock on both boards to 95MHz all is well. If I overclock
>> the mpc862 to 105 MHz it works fine.
>>
>> It turns out that syslog is actually running after the error. If I stop syslog and
>> start it again it works fine. If adjust my script so klogd is started before
>> syslogd all is well to.
>>
>> This looks like a race somewhere to me, but i have no clue as to where.
>>
>> Anyone?
>>
>>     Jocke
>
>hmm, if I upgrade the JFFS2 filesystem to CVS HEAD, the problem goes away.


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RE: Fast HDLC driver

[Joakim Tjernlund]

Hi Owen

I have written a patch to 8xx_io/enet.c that avoids copying. It still calls
netif_rx from IRQ context, but it's a start. The patch was posted a few weeks
ago to this list.

Could you post a copy of the qslinux hdlc driver? I am interested to se how
one would avoid calling netif_rx from IRQ context.

      Jocke
>
>
> Hi all,
>
> I`ve started working on a new project were a high
> performace hdlc channel is needed (at least 4Mbps on
> MPC8xx-50Mhz).
> I found several drivers for hdlc, but some are not
> very fast (copies memory,... ), most of them calls
> netif_rx from inside interrupt_handler (I don`t think
> this is the best place for doing that, watchdog may
> expire if the interface gets very busy..).
> The only driver I found that seems to be really fast
> and doesnt do all this stuff in interrupt context is
> for kernel-2.2 (QSLINUX).
> Does anyone ported this to 2.4 or knows another
> implementation of hdlc driver that could do this the
> way I`m thinking?
>
> Thanks in advance, Owen.
>
>
>
>


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Re: Fast HDLC driver

[Roland Dreier]

>>>>> "Owen" == Owen Green <owenjinggreen@yahoo.com> writes:

    Owen> most of them calls netif_rx from inside interrupt_handler (I
    Owen> don`t think this is the best place for doing that, watchdog
    Owen> may expire if the interface gets very busy..)

I don't have a specific answer about HDLC, but I think calling
netif_rx() from interrupt context is correct.  netif_rx() doesn't do
anything except queue the packet for processing and then mark the
network softirq.  In fact if you want to call netif_rx() from
non-interrupt context then you have to use the netif_rx_ni() function
to make sure the softirq runs soon enough.

Best,
  Roland

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Re: Fast HDLC driver

[Roland Dreier]

>>>>> "Ricardo" == Ricardo Scop <scop@digitel.com.br> writes:

    Roland> I don't have a specific answer about HDLC, but I think
    Roland> calling netif_rx() from interrupt context is correct.
    Roland> netif_rx() doesn't do anything except queue the packet for
    Roland> processing and then mark the network softirq.  In fact if
    Roland> you want to call netif_rx() from non-interrupt context
    Roland> then you have to use the netif_rx_ni() function to make
    Roland> sure the softirq runs soon enough.

    Ricardo> Hmm, is this true? QSLinux driver calls netif_rx() from
    Ricardo> thew interrupts bottom half; it it ok?

This should probably be OK.  First, a bottom half is still interrupt
context.  Second, if I recall correctly, Linux 2.2 does not even
define netif_rx_ni().  If the driver works well there's no reason to
change it.

Best,
  Roland


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Fast HDLC driver

[Owen Green]

Hi all,

I`ve started working on a new project were a high
performace hdlc channel is needed (at least 4Mbps on
MPC8xx-50Mhz).
I found several drivers for hdlc, but some are not
very fast (copies memory,... ), most of them calls
netif_rx from inside interrupt_handler (I don`t think
this is the best place for doing that, watchdog may
expire if the interface gets very busy..).
The only driver I found that seems to be really fast
and doesnt do all this stuff in interrupt context is
for kernel-2.2 (QSLINUX).
Does anyone ported this to 2.4 or knows another
implementation of hdlc driver that could do this the
way I`m thinking?

Thanks in advance, Owen.


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