SiS 191 failure with MTU > 1496

SiS 191 failure with MTU > 1496

[Pascal Terjan]

On a laptop with such hardware, with default 1500 MTU I can't connect to
local machines, error bit LIMIT is set when receiving packets.

By decreasing the MTU to 1496 everything works fine.

Jun 28 20:03:13 localhost kernel: sis190 Gigabit Ethernet driver 1.2
loaded.
Jun 28 20:03:13 localhost kernel: sis190 0000:00:04.0: PCI INT A -> GSI
19 (level, low) -> IRQ 19
Jun 28 20:03:13 localhost kernel: 0000:00:04.0: Read MAC address from
EEPROM
Jun 28 20:03:13 localhost kernel: 0000:00:04.0: Error EEPROM read 0.
Jun 28 20:03:13 localhost kernel: 0000:00:04.0: Read MAC address from
APC.
Jun 28 20:03:13 localhost kernel: 0000:00:04.0: Realtek PHY RTL8201
transceiver at address 1.
Jun 28 20:03:13 localhost kernel: 0000:00:04.0: Using transceiver at
address 1 as default.
Jun 28 20:03:13 localhost kernel: 0000:00:04.0: SiS 191 PCI Gigabit
Ethernet adapter at f08c0c00 (IRQ: 19), 00:21:85:da:e1:51
Jun 28 20:03:13 localhost kernel: eth0: GMII mode.
Jun 28 20:03:13 localhost kernel: eth0: Enabling Auto-negotiation.

00:04.0 0200: 1039:0191 (rev 02)
	Subsystem: 1462:63f8
	Flags: bus master, medium devsel, latency 0, IRQ 19
	Memory at fddfcc00 (32-bit, non-prefetchable) [size=128]
	I/O ports at cc00 [size=128]
	Capabilities: [40] Power Management version 2
	Kernel driver in use: sis190
	Kernel modules: sis190

Re: SiS 191 failure with MTU > 1496

[Pascal Terjan]

Le vendredi 29 mai 2009 à 18:44 +0200, Pascal Terjan a écrit :
> On a laptop with such hardware, with default 1500 MTU I can't connect to
> local machines, error bit LIMIT is set when receiving packets.
> 
> By decreasing the MTU to 1496 everything works fine.
> 

This looks like a known issue

http://bugzilla.kernel.org/show_bug.cgi?id=10895
https://bugs.launchpad.net/ubuntu/+bug/369513

Re: SiS 191 failure with MTU > 1496

[Pascal Terjan]

Le vendredi 29 mai 2009 à 18:50 +0200, Pascal Terjan a écrit :
> Le vendredi 29 mai 2009 à 18:44 +0200, Pascal Terjan a écrit :
> > On a laptop with such hardware, with default 1500 MTU I can't connect to
> > local machines, error bit LIMIT is set when receiving packets.
> > 
> > By decreasing the MTU to 1496 everything works fine.
> > 
> 
> This looks like a known issue
> 
> http://bugzilla.kernel.org/show_bug.cgi?id=10895
> https://bugs.launchpad.net/ubuntu/+bug/369513

Oh and even
http://bugzilla.kernel.org/show_bug.cgi?id=10694

Should I add some info there ?

Re: SiS 191 failure with MTU > 1496

[Francois Romieu]

Pascal Terjan <pterjan@mandriva.com> :
[...]
> Oh and even
> http://bugzilla.kernel.org/show_bug.cgi?id=10694

Yes, it sucks.

> Should I add some info there ?

Not yet but could you retry with RX_BUF_SIZE set to 1544,
1528 and 1520 ?

-- 
Ueimor

Re: SiS 191 failure with MTU > 1496

[Pascal Terjan]

Le samedi 30 mai 2009 à 00:30 +0200, Francois Romieu a écrit :
> Pascal Terjan <pterjan@mandriva.com> :
> [...]
> > Oh and even
> > http://bugzilla.kernel.org/show_bug.cgi?id=10694
> 
> Yes, it sucks.
> 
> > Should I add some info there ?
> 
> Not yet but could you retry with RX_BUF_SIZE set to 1544,
> 1528 and 1520 ?
> 

1544, 1528 and 1520 fail the same way

Re: SiS 191 failure with MTU > 1496

[Pascal Terjan]

Le mardi 02 juin 2009 à 13:50 +0200, Pascal Terjan a écrit :
> Le samedi 30 mai 2009 à 00:30 +0200, Francois Romieu a écrit :
> > Pascal Terjan <pterjan@mandriva.com> :
> > [...]
> > > Oh and even
> > > http://bugzilla.kernel.org/show_bug.cgi?id=10694
> > 
> > Yes, it sucks.
> > 
> > > Should I add some info there ?
> > 
> > Not yet but could you retry with RX_BUF_SIZE set to 1544,
> > 1528 and 1520 ?
> > 
> 
> 1544, 1528 and 1520 fail the same way

By the way there is some strange code:

tp->rx_buf_sz = (mtu > RX_BUF_SIZE) ? mtu + ETH_HLEN + 8 : RX_BUF_SIZE;

Isn't there a (different from the one I'm interested in :) ) bug when
1500 < mtu <= RX_BUF_SIZE

Shouldn't the test be (mtu > ETH_DATA_LEN) ?