Subject: Re: [e1000][net-2.6 tree] Regression: driver doesn't detect card on my node.

From: Yinghai Lu <[email-masked]>
Date: Wed, 06 Feb 2008 01:19:24 -0800

On Wednesday 06 February 2008 12:41:15 am Pavel Emelyanov wrote:
> Yinghai Lu wrote:
> > On Tuesday 05 February 2008 11:10:24 pm Pavel Emelyanov wrote:
> >> [snip]
> >>
> >>>>> What other info from me is required?
> >>> boot log please. with the patch and reverting the patch.
> >> Here they are (attached).
> >> BTW, I found, that the sky2 adapter is broken by this patch as well.
> >> To simplify the analysis, here's their diff:
> >>
> >> --- bad-log	2008-02-06 10:06:40.000000000 +0300
> >> +++ good-log	2008-02-06 10:06:40.000000000 +0300
> >> @@ -1,4 +1,4 @@
> >> -Linux version 2.6.24 (pavel@xemulnb) (gcc version 4.1.3 20070724 (prerelease) (SUSE Linux)) #22 SMP Tue Feb 5 20:09:11 MSK 2008
> >> +Linux version 2.6.24 (pavel@xemulnb) (gcc version 4.1.3 20070724 (prerelease) (SUSE Linux)) #23 SMP Wed Feb 6 10:03:53 MSK 2008
> >>  BIOS-provided physical RAM map:
> >>   BIOS-e820: 0000000000000000 - 000000000009f800 (usable)
> >>   BIOS-e820: 000000000009f800 - 00000000000a0000 (reserved)
> >> @@ -19,29 +19,6 @@ Scan SMP from c0000000 for 1024 bytes.
> >>  Scan SMP from c009fc00 for 1024 bytes.
> >>  Scan SMP from c00f0000 for 65536 bytes.
> >>  found SMP MP-table at [c00ff780] 000ff780
> >> -***************
> >> -**** WARNING: likely BIOS bug
> >> -**** MTRRs don't cover all of memory, trimmed 786432 pages
> >> -***************
> >> -update e820 for mtrr
> >> -modified physical RAM map:
> >> - modified: 0000000000000000 - 000000000009f800 (usable)
> >> - modified: 000000000009f800 - 00000000000a0000 (reserved)
> >> - modified: 00000000000e0000 - 0000000000100000 (reserved)
> >> - modified: 0000000000100000 - 0000000040000000 (usable)
> >> - modified: 0000000040000000 - 00000000bfff0000 (reserved)
> >> - modified: 00000000bfff0000 - 00000000bffff000 (ACPI data)
> >> - modified: 00000000bffff000 - 00000000c0000000 (ACPI NVS)
> >> - modified: 00000000c0000000 - 0000000100000000 (reserved)
> >> - modified: 0000000100000000 - 0000000140000000 (usable)
> > 
> > the root cause could be your mtrr last entry for RAM has strange type
> > 
> > please apply the following line to print the mtrr before trimming to current linus tree.
> 
> OK, here's the dmesg diff:
> --- bad-log     2008-02-06 10:01:21.000000000 +0300
> +++ bad-log-info        2008-02-06 11:37:51.000000000 +0300
> @@ -19,6 +19,14 @@ Scan SMP from c0000000 for 1024 bytes.
>  Scan SMP from c009fc00 for 1024 bytes.
>  Scan SMP from c00f0000 for 65536 bytes.
>  found SMP MP-table at [c00ff780] 000ff780
> +i=0 c0000 - 100000 0
> +i=1 0 - 100000 6
> +i=2 100000 - 140000 6
> +i=3 0 - 0 0
> +i=4 0 - 0 0
> +i=5 0 - 0 0
> +i=6 0 - 0 0
> +i=7 0 - 0 0
>  ***************
>  **** WARNING: likely BIOS bug
>  **** MTRRs don't cover all of memory, trimmed 786432 pages

please try following patch

diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 1e27b69..4e7490f 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -659,7 +659,7 @@ static __init int amd_special_default_mtrr(void)
  */
 int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
 {
-	unsigned long i, base, size, highest_addr = 0, def, dummy;
+	unsigned long i, base, size, highest_pfn = 0, def, dummy;
 	mtrr_type type;
 	u64 trim_start, trim_size;
 
@@ -682,28 +682,27 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
 		mtrr_if->get(i, &base, &size, &type);
 		if (type != MTRR_TYPE_WRBACK)
 			continue;
-		base <<= PAGE_SHIFT;
-		size <<= PAGE_SHIFT;
-		if (highest_addr < base + size)
-			highest_addr = base + size;
+		if (highest_pfn < base + size)
+			highest_pfn = base + size;
 	}
 
 	/* kvm/qemu doesn't have mtrr set right, don't trim them all */
-	if (!highest_addr) {
+	if (!highest_pfn) {
 		printk(KERN_WARNING "WARNING: strange, CPU MTRRs all blank?\n");
 		WARN_ON(1);
 		return 0;
 	}
 
-	if ((highest_addr >> PAGE_SHIFT) < end_pfn) {
+	if (highest_pfn < end_pfn) {
 		printk(KERN_WARNING "WARNING: BIOS bug: CPU MTRRs don't cover"
 			" all of memory, losing %LdMB of RAM.\n",
-			(((u64)end_pfn << PAGE_SHIFT) - highest_addr) >> 20);
+			(end_pfn - highest_pfn) >> (20 - PAGE_SHIFT));
 
 		WARN_ON(1);
 
 		printk(KERN_INFO "update e820 for mtrr\n");
-		trim_start = highest_addr;
+		trim_start = highest_pfn;
+		trim_start <<= PAGE_SHIFT;
 		trim_size = end_pfn;
 		trim_size <<= PAGE_SHIFT;
 		trim_size -= trim_start;

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