plx problem on soft reboot

Pavel Roskin proski
Mon Mar 8 11:44:20 PST 2004

On Mon, 8 Mar 2004, Santiago Garcia Mantinan wrote:

> I have changed the pci adapter in my AP from a pcmcia to a plx today,
> and I found this weird behaviour...
> It seems that the card works well first time machine is booted, if you
> do a soft reboot the plx driver won't work on boot until you do: a
> hardware reset power off and on the machine again remove the pcmcia card
> and plug it on again

I have never seen this behavior, but the fix should be to make it possible
for the drive to initialize the adapter in any state.

What I see in the code is that prism2_plx_cor_sreset() is called from
prism2_plx_remove(), i.e. when the module is removed, but not from
prism2_plx_probe() called when the device is initialized.

Try this patch (not tested, not ready for applying yet):

--- driver/modules/hostap_plx.c
+++ driver/modules/hostap_plx.c
@@ -520,6 +520,8 @@ static int prism2_plx_probe(struct pci_d
 	} else
 		irq_registered = 1;

+	prism2_plx_cor_sreset(local);
 	if (prism2_hw_config(dev, 1)) {
 		printk(KERN_DEBUG "%s: hardware initialization failed\n",

> hostap_plx: Registered netdevice wlan0
> wlan0: Command completion event, but no pending commands

This probably indicates that the card is still running despite the reboot.

> I've seen however that if before the reboot I do a modprobe -r hostap_plx
> then everything is ok when it boots up again.

Because it calls prism2_plx_cor_sreset().

> One unrelated question... is there any way to know what voltage does the PLX
> adaptor use?

Look for "pci voltage keying" on Google.  This document has an
illustration on the first page:

Pavel Roskin

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