Can't read e1000 NIC EEPROM on NetBSD guest

[Izumi Tsutsui]

QEMU Version: qemu-0.12.4
Host OS: NetBSD/i386 5.0.2
Guest OS: NetBSD/i386 5.1_RC1

On this environment, guest NetBSD tries to attach e1000 NIC using its own wm(4) driver but fails to read EEPROM as the following:
---
NetBSD 5.1_RC1 (GENERIC) #0: Sat Apr 24 23:26:09 UTC 2010
        <email address hidden>:/home/builds/ab/netbsd-5-1-RC1/i386/201004250032Z-obj/home/builds/ab/
netbsd-5-1-RC1/src/sys/arch/i386/compile/GENERIC
total memory = 127 MB
avail memory = 113 MB
Bochs Bochs
 :
drm at vga1 not configured
wm0 at pci0 dev 3 function 0: Intel i82540EM 1000BASE-T Ethernet, rev. 3
wm0: interrupting at irq 11
wm0: unable to read Ethernet address
isa0 at pcib0
 :
---

You can reproduce this with NetBSD/i386 install CD image:
 ftp://ftp.NetBSD.org/pub/NetBSD/NetBSD-5.1_RC1/iso/i386cd-5.1_RC1.iso
 % qemu -cdrom i386cd-5.1_RC1.iso -boot d
 ---in QEMU window---
 [type ^C to quit installer]
 # dmesg | grep wm0
------

Per DBGOUT(EEPROM) messages, it show too large eecd_state.bitnum values, i.e. EEPROM state is not reset properly.
The set_eecd() function in e1000.c clears EEPROM internal state values on SK rising edge during CS==L.
But according to FM93C06 EEPROM (which is MicroWire compatible) data sheet,
EEPROM internal status should be cleared on CS rise edge regardless of SK input:
 "... a rising edge on this signal is required to reset the internal state-machine to accept a new cycle .."

Intel's em driver seems to explicitly raise and lower SK output after CS is negated in em_standby_eeprom()
so many other OSes that use Intel's driver don't have this problem with current e1000.c implementation,
but I can't find articles that say the MICROWIRE or EEPROM spec requires such sequence.

With the attached patch, NetBSD guest properly gets MAC address from e1000 NIC EEPROM.

[Ryan Harper (raharper)]

I applied this patch against qemu.git and it does indeed fix the issue for netbsd referenced in the bug. Please submit this patch against upstream qemu.git and include a Signed-off-by: in the patch.

[Ryan Harper (raharper)]

Please email the patch to <email address hidden> via git-send-email. This will ensure the maintainers see the patch and the community has a chance to review the patch.

[Izumi Tsutsui (tsutsui)]

> Please email the patch to <email address hidden> via git-send-email.
Isn't the following post enough? What's incomplete on this?
http://lists.nongnu.org/archive/html/qemu-devel/2010-06/msg00449.html
(sorry I'm not familiar with git)

[Andreas Färber (afaerber)]

Am 13.06.2010 um 07:16 schrieb Izumi Tsutsui:

>> Please email the patch to <email address hidden> via git-send-email.
> Isn't the following post enough? What's incomplete on this?
> http://lists.nongnu.org/archive/html/qemu-devel/2010-06/msg00449.html

That is still not a proper git-format-patch patch, it is missing among
others the From: and Subject: lines and, likely, a more detailled
description of what it does and why, for maintainers to be able to
apply it with the git-am tool.

But first it needs to be reviewed and ack'ed by people knowing that
part of the code, and such review is done by inline patches on qemu-
devel mailing list, not by HTTP links to bugtrackers (there are simply
too many patches). The git-send-email tool assures that the format is
not damaged by your favorite mail agent.

Hope that explains,

Andreas

[Izumi Tsutsui (tsutsui)]

> >> Please email the patch to <email address hidden> via git-send-email.
> > Isn't the following post enough? What's incomplete on this?
> > http://lists.nongnu.org/archive/html/qemu-devel/2010-06/msg00449.html
>
> That is still not a proper git-format-patch patch, it is missing among
> others the From: and Subject: lines and, likely, a more detailled
> description of what it does and why, for maintainers to be able to
> apply it with the git-am tool.

Whole description is in the bug report itself.
git-format-patch is strictly required even in such case?
If so, is there any proper documents how to submit patches for QEMU?
---
Izumi Tsutsui

[Andreas Färber (afaerber)]

Am 13.06.2010 um 14:50 schrieb Izumi Tsutsui:

>>>> Please email the patch to <email address hidden> via git-send-email.
>>> Isn't the following post enough? What's incomplete on this?
>>> http://lists.nongnu.org/archive/html/qemu-devel/2010-06/
>>> msg00449.html
>>
>> That is still not a proper git-format-patch patch, it is missing
>> among
>> others the From: and Subject: lines and, likely, a more detailled
>> description of what it does and why, for maintainers to be able to
>> apply it with the git-am tool.
>
> Whole description is in the bug report itself.
> git-format-patch is strictly required even in such case?

A self-contained description is required for the commit in the
(distributed) Git repository.

http://www.spheredev.org/wiki/Git_for_the_lazy#Writing_good_commit_messages
http://git.qemu.org/qemu.git/log/

> If so, is there any proper documents how to submit patches for QEMU?

http://wiki.qemu.org/Contribute/StartHere
http://git.qemu.org/qemu.git/plain/CODING_STYLE
http://www.kernel.org/pub/software/scm/git/docs/gitworkflows.html#_patch_workflow

It's not too QEMU-specific, so any Git tutorial should do.

HTH,
Andreas