[ELDK] ppc boot fails at PCI detection.

[Larry Johnson]

renjith kumar wrote:
> hi ,
> 
> I get kernel hanging problem after "*Uncompressing Kernel Image ... OK*".
> message. (Not always , but most of the time :( ..)
> I use the ppc_4xxFP based Sequoia board with 2 PCI slots.
> 
> When I remove/comment the function , sequoia_setup_hose() for PCI card
> detection ,
> the kernel boots without any problem (But without PCI support).
> 
> I was just wondering , Has anybody experienced similar problem ??
> Was there any problem with PCI part, for power PC reported before ??


There is a known bug in the latest version of Linux kernel file
arch/powerpc/sysdev/ppc4xx_pci.c that causes the PCI to fail for at
least some PPC440 processors, including the PPC440EPx. Until a general
solution is added to the Linux distribution, I have been using the
following patch on my PPC440EPx board:



diff --git a/arch/powerpc/sysdev/ppc4xx_pci.c b/arch/powerpc/sysdev/ppc4xx_pci.c
index 77fae5f..1d87e5e 100644
--- a/arch/powerpc/sysdev/ppc4xx_pci.c
+++ b/arch/powerpc/sysdev/ppc4xx_pci.c
@@ -204,8 +204,9 @@ static int __init ppc4xx_setup_one_pci_PMM(struct pci_controller	*hose,
 {
 	u32 ma, pcila, pciha;
 
-	if ((plb_addr + size) > 0xffffffffull || !is_power_of_2(size) ||
-	    size < 0x1000 || (plb_addr & (size - 1)) != 0) {
+	if ((plb_addr + size - (1ull << 32)) > (1ull << 32) - 1ull ||
+	   !is_power_of_2(size) || size < 0x1000 ||
+	   (plb_addr & (size - 1)) != 0) {
 		printk(KERN_WARNING "%s: Resource out of range\n",
 		       hose->dn->full_name);
 		return -1;



Please note that I have no idea whether this patch would work for
processors other than the EPx/GPx.  I'd recommend that you apply this
patch and rebuild your kernel to see if it helps.

Best regards,
Larry Johnson