[Prism54-users] terminal prism54 performance problems

[Luis R. Rodriguez]

On Wed, Aug 18, 2004 at 09:39:09PM +0100, Paul Jakma wrote:
> Hi,
> 
> I'm experiencing severe problems (ie doesnt work) with the prism54 
> driver. Setup:
> 
> APs:
> 
> 2x Netgear WG602v2 with latest 3.2rc6 firmware (upgraded from 3.1rc5 
> iirc, made no difference to problem). I have tried with preamble set 
> to both mixed and long. The 2 APs are in multipoint-bridging mode, 
> with about 86% link strength between them, one bridging the wireless 
> network onto 100BaseT network. I'm using WEP128 on the wireless 
> links.
> 
> I can ping flood from the 100BaseT network, over the wireless link to 
> the wireless only AP with 0 packet loss:
> 
> --- 192.168.0.9 ping statistics ---
> 312 packets transmitted, 312 received, 0% packet loss, time 3887ms
> rtt min/avg/max/mdev = 1.913/5.146/90.770/12.389 ms, pipe 8, ipg/ewma 
> 12.499/2.276 ms
> 
> So that link is good.
> 
> The wireless only AP provides service to a single client:
> 
> Sony Vaio PCG-C1F with built-in Ricoh RL5c475 cardbus controller
> WG511 Cardbus Prism54 802.11g card
> 1.0.4.3 Prism54 firmware[1]
> Fedora Core 2 Linux
> Arjan's 2.6.8-1.521 FC kernel package
> 
> With the driver provided in the 2.6.8-1.521 kernel, which i think is 
> prism54 1.2, the computer locks up after any decent amount of traffic 
> (eg downloading a file from the internet, which would be limited to 
> ~50kB/s due to DSL, or ping -f -s 1500). The yellow light on the 
> WG511 still flickers, indicating, I presume that it's still receiving 
> occassional wireless traffic, however the computer is dead, other 
> than the console cursor still blinking (which i think is done in 
> hardware). The keyboard is completely unresponsive, num/caps lock 
> dont work, not even alt+sysrq works, so presumably the prism54 is 
> stuck somewhere with interrupts disabled.

Just the keyboard right? You can still use the mouse? I've seen this
happen to me only when using a display manager (gdm, kdm, xmd). I didn't
look further into it.

Regarding the high traffic flow causing problems:

Some have reported this but I am unable to reproduce. I can pass ongoing
data accross my card and nothing will hang it. I have the 3com. It may
be the case 3com uses Prism GT and the network traffic problems are
occuring on Prism Frisbee based cards. My understanding is Frisbee
chipset based cards (apparantly most on the market) just has a cheaper
Zero-IF (ZIF) architecture. Not sure if this could have an effect on
traffic jams.

Some sources, good read:
http://www.commsdesign.com/design_corner/showArticle.jhtml?articleID=12802011

> 
> If I manually eject the WG511, the PC becomes responsive again. If I 
> insert the WG511 again, it will be configured by cardctl and brought 
> up, when that occurs the PC will die again, irretrievably, needing a 
> hard reboot.
> 
> I also tried with latest CVS. I downloaded ksrc as of about 1500GMT 
> and compiled it. With this I get an almost instant panic, each time 
> with EIP in wireless_spy_update(), from islpci_eth_receive() from 
> do_IRQ context, with lspci_interrupt() somewhere in the call path 
> between do_IRQ and islpci_eth_receive() (there'll be other interrupt 
> handlers there sometimes, eg acpi or atkbd. this laptop seems to have 
> nearly everything wired to irq 9 for some reason).

Please try again with the latest CVS as CVS had some errors and were
recenlty fixed -- see ChangeLog for details.

> I have tried booting acpi=off and acpi=on. No difference. Note that I 
> boot with pci=usepirqmask, without that the prism54 wont work at all.
> 
> Suggestions/debugging advice would be appreciated, and I'd be glad to 
> provide any more specific information that is desired.

Try 1.0.3.0 as its been reported is more stable.

> 1. I'd love to hear from someone with newer firmware. I tried running 
> Netgear's latest Windows driver update under WiNE to try extract 
> their firmware, but it didnt work.

I know of no newer firmware. After those I believe the softmac driver
was the focus of development.

Let us know how it goes. If problems persists, please e-mail
prism54-devel instead.

	Luis

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