Athlon Gigabyte GA-7IX mainboard is unstable with 3Com ethernet-cards, partially solved

[Moritz Franosch]

Hello,

We use an AMD Athlon K7 processor with a Gigabyte GA-7IX mainboard.

During transferring about 100 MB over the network by NFS the system
locked totally (you could not ping it, the keyboard LEDs did not react,
you could not switch virtual consoles).

This was the case for both 3Com 3c900 Boomerang and 3Com 3c905C
Tornado ethernet cards using the 3c59x driver. We tried the kernels
2.2.12, 2.2.13 and 2.3.31 without success.
An SMC Ultra ISA ethernet card worked stable.

We thought the reason for the instability could be the bus-master DMA
feature of the network cards. So we patched the 3c59x driver (the
patch is appended at the bottom).
This patch disabled the bus-master DMA. The 3c900 Boomerang works
stable with it, the 3c905C Tornado does not work at all with the
patch.

The 3c90x driver provided by 3Com
(http://support.3com.com/infodeli/tools/nic/linuxdownload.htm) shows
the same symptoms.
All 3Com-cards work stable on other mainboards.

I could not yet find out whether other PCI ethernet cards with
UDMA enabled work on the Gigabyte GA-7IX mainboard.

I have already tried to use the debug-option of the driver, but either 
I got (almost) no output or far too much.

If I can do something to find the problem or if you need more
information, please mail.


Thank you,

Moritz




Patch for the 3c59x driver:

*** linux-2.2.13/drivers/net/3c59x.c    Wed Oct 20 02:14:01 1999
--- linux-2.2.13.my3com.k7/drivers/net/3c59x.c  Wed Dec  8 20:06:15 1999
***************
*** 425,429 ****

  /* Chip features we care about in vp->capabilities, read from the EEPROM. */
! enum ChipCaps { CapBusMaster=0x20 };

--- 425,432 ----

  /* Chip features we care about in vp->capabilities, read from the EEPROM. */
! /* orig: enum ChipCaps { CapBusMaster=0x20 }; */
! /* modification disables bus-master DMA for */
! /* Gigabyte 7iX K7 (Athlon) Mainboard */
! enum ChipCaps { CapBusMaster=0x00 };


Boot messages (both machines have exactly the same hardware):

ampa kernel: 3c59x.c:v0.99H 11/17/98 Donald Becker http://cesdis.gsfc.nasa.gov/linux/drivers/vo
ampa kernel: eth0: 3Com 3c905C Tornado at 0xe400,  00:50:04:ef:bc:9e, IRQ 11
ampa kernel:   Internal config register is 1800000, transceivers 0xa.
ampa kernel:   8K byte-wide RAM 5:3 Rx:Tx split, autoselect/Autonegotiate interface.
ampa kernel:   MII transceiver found at address 24, status 782d.
ampa kernel:   Enabling bus-master transmits and whole-frame receives.

soma kernel: 3c59x.c:v0.99H 11/17/98 Donald Becker http://cesdis.gsfc.nasa.gov/linux/drivers/vortex.html
soma kernel: eth0: 3Com 3c900 Boomerang 10Mbps Combo at 0xe400,  00:60:97:7c:76:26, IRQ 15
soma kernel:   8K word-wide RAM 3:5 Rx:Tx split, 10baseT interface.