Re: Is the change to IDE probing really necessary?
From: Mel Gorman
Date: Mon Nov 24 2008 - 13:43:38 EST
On Mon, Nov 24, 2008 at 03:56:32PM +0000, Mel Gorman wrote:
> Hi,
>
> I got caught by commit 20df429dd6671804999493baf2952f82582869fa as I didn't
> immediately guess that "ide_generic." was necessary on the kernel command line
> when compiled in instead of as a module. While it didn't catch me for long,
> my concern is that this is going to trip up other people with old machines
> that need that mask. This change was introduced in 2.6.28-rc1 but I didn't
> catch it till now as I hadn't used the laptop in a while.
>
It gets even more screwy. Networking was bust on the machine when
the probe_mask workaround was used. After some investigation, I saw
/proc/interrupts looks like
CPU0
0: 55495 XT-PIC-XT timer
1: 8 XT-PIC-XT i8042
2: 0 XT-PIC-XT cascade
3: 1 XT-PIC-XT
4: 1763 XT-PIC-XT serial
6: 5 XT-PIC-XT floppy
8: 0 XT-PIC-XT ide4
9: 289 XT-PIC-XT acpi
10: 0 XT-PIC-XT ide3
11: 0 XT-PIC-XT ide2
12: 0 XT-PIC-XT ide5
14: 473802 XT-PIC-XT ide0
15: 209 XT-PIC-XT ide1
NMI: 0 Non-maskable interrupts
LOC: 0 Local timer interrupts
RES: 0 Rescheduling interrupts
CAL: 0 function call interrupts
TLB: 0 TLB shootdowns
SPU: 0 Spurious interrupts
ERR: 0
MIS: 0
Note the number of "ide" devices (2, 3 and 5) even though there are only
really two in the machine for the disk and cdrom. The file in 2.6.27 looked like
CPU0
0: 9881 XT-PIC-XT timer
1: 8 XT-PIC-XT i8042
2: 0 XT-PIC-XT cascade
4: 305 XT-PIC-XT serial
6: 5 XT-PIC-XT floppy
9: 141 XT-PIC-XT acpi
11: 136 XT-PIC-XT uhci_hcd:usb1, eth0
12: 149 XT-PIC-XT i8042
14: 54276 XT-PIC-XT ide0
15: 172 XT-PIC-XT ide1
Note how interrupt 11 is the ethernet on a working kernel and an ide device
with the suggested probe_mask. Using the old probe_mask of 0x3 instead of
0.3f works as expected so very minimally, could you consider the following
patch please?
====
From: Mel Gorman <mel@xxxxxxxxx>
Subject: [PATCH] ide_generic: Suggest 0x3 as a probe mask instead of 0x3f
On a machine requiring probing of the legacy ports, the suggested
probe_mask of 0x3f results in other devices being registered as IDE
devices. Suggest to the user they use 0x3 which is the old value of
probe_mask prior to commit 20df429dd6671804999493baf2952f82582869fa.
Signed-off-by: Mel Gorman <mel@xxxxxxxxx>
---
drivers/ide/ide-generic.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/ide/ide-generic.c b/drivers/ide/ide-generic.c
index 81a5282..7d6bd99 100644
--- a/drivers/ide/ide-generic.c
+++ b/drivers/ide/ide-generic.c
@@ -144,7 +144,7 @@ static int __init ide_generic_init(void)
ide_generic_check_pci_legacy_iobases(&primary, &secondary);
if (!probe_mask) {
- printk(KERN_INFO DRV_NAME ": please use \"probe_mask=0x3f\" "
+ printk(KERN_INFO DRV_NAME ": please use \"probe_mask=0x3\" "
"module parameter for probing all legacy ISA IDE ports\n");
if (primary == 0)
--
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