Re: tg3 broken on 2.6.17-rc5-mm3

[Bjorn Helgaas <bjorn.helgaas@hp.com>]

On Thursday 08 June 2006 23:03, H. Peter Anvin wrote:
> Bjorn Helgaas wrote:
> > On Wednesday 07 June 2006 17:11, Bjorn Helgaas wrote:
> >> Something changed between 2.6.17-rc5-mm2 and -mm3 that broke tg3
> >> on my HP DL360:
> > 
> > and the specific change that broke it seems to be:
> >   gregkh-pci-pci-ignore-pre-set-64-bit-bars-on-32-bit-platforms.patch.
> > 
> > pci_read:  0000:01:02.0 reg 0x10 len 4 val 0xf7ef0004
> > pci_write: 0000:01:02.0 reg 0x10 len 4 val 0xffffffff
> > pci_read:  0000:01:02.0 reg 0x10 len 4 val 0xffff0004
> > pci_write: 0000:01:02.0 reg 0x10 len 4 val 0xf7ef0004
> > pci_read:  0000:01:02.0 reg 0x14 len 4 val 0x0000
> > pci_write: 0000:01:02.0 reg 0x14 len 4 val 0xffffffff
> > pci_read:  0000:01:02.0 reg 0x14 len 4 val 0xffffffff
> > pci_write: 0000:01:02.0 reg 0x14 len 4 val 0x0000
> 
> ... this is a 64-bit BAR preset with a 16-bit mask, preset
> to the valid 32-bit address 0x0000_0000_f7ef_0000.
> 
> > pci_write: 0000:01:02.0 reg 0x10 len 4 val 0x0004  <=== looks questionable
> > pci_write: 0000:01:02.0 reg 0x14 len 4 val 0x0000
> 
> ... here the algorithm thinks the addrss is above 4 GB and disables it. 
>   It should re-enable it when the device is turned back on, though; if 
> it doesn't that's very strange.
> 
> Anyway, the error seems to be that the line:
> 
> +			} else if (l) {
> 
> ... should be ...
> 
> +			} else if (lhi) {
> 
> ... since l contains the lower half of the pre-set address at that 
> point, and lhi is the upper half.

The patch below indeed fixes the problem.  You can have my
"signed-off" if you want (though you supplied the fix above),
but can you please write the description?  I'm too lazy to
puzzle it all out and you understand it already anyway :-)


Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>

Index: rc5-mm3/drivers/pci/probe.c
===================================================================
--- rc5-mm3.orig/drivers/pci/probe.c	2006-06-09 09:40:51.000000000 -0600
+++ rc5-mm3/drivers/pci/probe.c	2006-06-09 09:42:35.000000000 -0600
@@ -199,7 +199,7 @@
 				printk(KERN_ERR "PCI: Unable to handle 64-bit BAR for device %s\n", pci_name(dev));
 				res->start = 0;
 				res->flags = 0;
-			} else if (l) {
+			} else if (lhi) {
 				/* 64-bit wide address, treat as disabled */
 				pci_write_config_dword(dev, reg, l & ~(u32)PCI_BASE_ADDRESS_MEM_MASK);
 				pci_write_config_dword(dev, reg+4, 0);