playing with qemu's 8139 nic and FreeBSD (loopback mode missing?

[Juergen Lock]

On Sun, May 07, 2006 at 12:38:06AM +0400, Igor Kovalenko wrote:
> Hi Juergen,
> 
> Juergen Lock wrote:
> >[Cc'ing glebius@ because he did most of the recent re(4) commits, and
> >-current in case possible other driver developers didn't see this thread
> >in -emulation]
> >
> >On Wed, May 03, 2006 at 07:46:07AM +0400, Igor Kovalenko wrote:
> >>Juergen Lock wrote:
> >>>On Sat, Apr 29, 2006 at 10:48:48AM +0400, Igor Kovalenko wrote:
> >>>>Juergen Lock wrote:
> >>>>>On Fri, Apr 28, 2006 at 08:25:02PM +0400, Igor Kovalenko wrote:
> >>>>>>Juergen Lock wrote:
> >>>>>>>I played with
> >>>>>>>	qemu -monitor stdio -m 256 -cdrom 6.1-RC1-i386-disc1.iso 
> >>>>>>>	-usb -soundhw es1370 -kernel-kqemu -net nic,model=rtl8139 
> >>>>>>>	-net user
> >>>>>>>and got it as far as
> >>>>>>>	re0: diagnostic failed, failed to receive packet in loopback 
> >>>>>>>	mode
> >>>>>>>(followed by a panic :) with the (experimental) patches below.
> >>>>>>>
> >>>>>>> Anyone in the mood to implement loopback mode for this nic?
> >>>>>>>
> >>>>>>> Hmm actually...  I just found the original posting in the archive,
> >>>>>>>is C+ mode implemented now?  If not re is probably not what I want,
> >>>>>>The rtl8139 is set up with PCI rev ID 0x20 which should be enough for 
> >>>>>>OS driver
> >>>>>>to detect C+ mode features. C+ mode is OK, tested with Linux driver.
> >>>>>Cool, so I want FreeBSD's re driver.  That one checks TxConfig
> >>>>>tho, as changed in my patch (inside #if 0).  And when changed,
> >>>>>it still doesn't work as mentioned above because the driver expects
> >>>>>loopback mode to be working.
> >>>>>>>but the rl driver that it attaches without that #if 0'd (now) hunk
> >>>>>>>below doesnt seem to be able to get data thru either and I get
> >>>>>>>	rl0: watchdog timeout
> >>>>>>>in dmesg, which usually means the driver doesnt receive interrupts.
> >>>>>>>
> >>>>>>> What the heck, I'll append a log of a run just doing in 
> >>>>>>> fixit->cdrom:
> >>>>>>>	ifconfig rl0 10.0.2.15
> >>>>>>>and then exiting (which is enough to trigger the watchdog timeout...)
> >>>>>>>
> >>>>>>I'm too lasy to test with fresh freebsd installation :)
> >>>>> No need to install FreeBSD, you can get away by just using
> >>>>>fixit mode of an install iso, i.e. disc1.  (which actually is
> >>>>>what I did above. :)
> >>>>>
> >>>>> You can look at 6.1RC's re driver here:
> >>>>>http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/dev/re/if_re.c?annotate=1.46.2.14
> >>>>> which includes:
> >>>>>http://www.freebsd.org/cgi/cvsweb.cgi/src/sys/pci/if_rlreg.h?annotate=1.51.2.3
> >>>>>
> >>>>> And 6.1RC disc1 iso is e.g. here:
> >>>>>ftp://ftp.ru.freebsd.org:/pub/FreeBSD/ISO-IMAGES-i386/6.1/6.1-RC1-i386-disc1.iso
> >>>>>
> >>>>>
> >>>>Thanks, that iso pointer made it.
> >>>>
> >>> :)
> >>>
> >>>>Please try the following on top of your patch, at least ping should now 
> >>>>work:
> >>> Thanks, that seems to get the rl driver going.  Now to fix C+ mode
> >>>(re driver) change the #if 0 in my patch to #if 1...
> >>>
> >>>
> >>I believe freebsd re driver is somewhat broken, e.g. it does not follow 
> >>documented
> >>procedure to detect hardware features (e.g. 8139 c+ mode)
> >
> >Hmm, a bit of googling didn't reveal docs about this, do you have
> >a pointer?  (I only found the data sheet at
> >	http://people.freebsd.org/~wpaul/RealTek/spec-8139cp(150).pdf
> >which doesnt seem to mention detecting c+ hardware specifically)
> 
> Well, I might have misread some docs; please do not consider this as an 
> assault :)
> I remember PCI rev id >= 0x20 is C+ mode for realtek 8139.

I don't.  It may well be the doc you saw this in just is no longer
online, or I didn't came up with the right search terms...
> 
> >
> >> and in tries to use 8169
> >>registers (e.g. 0xda) on 8139 hardware etc.
> >
> > Oh, then it must have mis-detected the nic as a 8169 because
> >the code in question reads:
> >
> >        if (sc->rl_type == RL_8169)
> >                CSR_WRITE_2(sc, RL_MAXRXPKTLEN, 16383);

 And with your patch i get
	RTL8139: not implemented write(b) addr=0xda val=0x00
but that can't be this line anyway because it seems to be a byte access...
Any of the re(4) experts have an idea where this comes from?
(log generated by defining DEBUG_RTL8139 in the patched hw/rtl8139.c)

> >>Therefore some action from driver people is needed; I can provide a patch 
> >>which
> >>enables board timer in rtl8139 emulation (and thus enables hardware 
> >>timeout
> >>events) if you need it.
> >
> > Yeah I guess that would be useful...
> >
> >
> 
> Please find rtl8139.c.freebsd.timer.diff attached hereto.
> The diff contains part of your changes to chip identification so re driver
> does see it as C+ mode chip. Timer support is added (and there is no kpanic 
> now),
> though the specs require it to be clocked with PCI bus; that is somewhat 
> hard
> to achieve. Common qemu timer is of much lower resolution; doing it 
> differently
> will require some effort.

 Thankx!  (I doubt cycle accuracy is really needed here anyway, and
afaik nowhere else in qemu is that done either.)