Re: /dev/hdl not showing up because of fix-ide-probe-double-detection patch

[Tupshin Harper1 <tupshin@tupshin.com>]

Tupshin Harper1 wrote:

> I have an x86 setup with a large(9) number of ide hard drives. With 
> 2.6.8-rc2, all of them show up (as a,b,d,e,f,g,h,i,j,k, and l), but on 
> 2.6.8-rc2-mm1, the last one (hdl) does not show up, even though it's a 
> slave on the same controller as hdk. Everything about the config is 
> identical between the two. Is there some default limit or other 
> restriction in the current mm kernels that's preventing that drive 
> from showing up? I haven't tried any other recent mm kernels, so I 
> don't know when this was introduced.
>
> -Tupshin

Well, I found the source of the problem. Dmesg gives a "ignoring 
undecoded slave" message, which is coming from the 
fix-ide-probe-double-detection patch.

Both /dev/hdk and /dev/hdl are the same model of hard drive, and 
unfortunately, they both report that they are Model 
M0000000000000000000, which triggers the double detection removal.

Does anybody have a suggestion (besides maintaining my own kernel 
without this patch)? Is the serial number settable? Is there a boot 
param I can use?

Also, what is in /proc/ide/hd?/identity besides serial number. The two 
drives have very similar identity files, but they are slightly 
different. Could that additional info be used to check for duplicates?

-Tupshin

---snippet from dmesg---
PDC20276: IDE controller at PCI slot 0000:00:0c.0
ACPI: PCI interrupt 0000:00:0c.0[A] -> GSI 19 (level, low) -> IRQ 19
PDC20276: chipset revision 1
PDC20276: 100% native mode on irq 19
    ide4: BM-DMA at 0xdc00-0xdc07, BIOS settings: hdi:pio, hdj:pio
    ide5: BM-DMA at 0xdc08-0xdc0f, BIOS settings: hdk:pio, hdl:pio
hdi: SAMSUNG SV8004H, ATA DISK drive
hdj: Maxtor 6Y250P0, ATA DISK drive
ide4 at 0xec00-0xec07,0xe802 on irq 19
hdk: Maxtor 4R120L0, ATA DISK drive
hdl: Maxtor 4R120L0, ATA DISK drive
ide-probe: ignoring undecoded slave
ide5 at 0xe400-0xe407,0xe002 on irq 19