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

Hi Juergen,

Juergen Lock wrote:
> [Cc'ing glebius_at_ 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.

> 
>>  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);
>> 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.

-- 
Kind regards,
Igor V. Kovalenko