Re: [PATCH #upstream-fixes 1/4] libata: fix device iteration bugs

[Tejun Heo <tj@kernel.org>]

Hello,

Michael Guntsche wrote:
> ata_piix 0000:00:07.1: version 2.12
> scsi0 : ata_piix
> scsi1 : ata_piix
> ata1: PATA max MWDMA2 cmd 0x1f0 ctl 0x3f6 bmdma 0xe800 irq 14
> ata2: PATA max MWDMA2 cmd 0x170 ctl 0x376 bmdma 0xe808 irq 15
> ata1.00: ATA-5: IC35L040AVER07-0, ER4OA45A, max UDMA/100
> ata1.00: 66055248 sectors, multi 16: LBA
> ata1.00: configured for MWDMA2
> ata2.01: NODEV after polling detection
> ata2.00: ATAPI: SAMSUNG CD-R/RW SW-408B, M300, max MWDMA2
> ata2.00: configured for MWDMA2
> 
> This is the output I get. I do not know if I have any stalls there since I
> am not in front of the machine right now.
> But if I understand "NODEV after polling detection" correctly, the code is
> no able to see that there is nothing attached there.
> I will give it another reboot when I am back home to see if the stall is
> still happening.

Yeap, it's working correctly now.

> On a side note, since we are already talking about old chipsets and mobos.
> Since this is a rather old hardware it was not possible to get the 40GB IBM
> disk running in the first place. 
> What I did back then (2.4 kernel days) was to use "ibmsetmax" to clamp the
> disk to a smaller size and enabled the relevent option in the kernel. This
> way I got past the BIOS (it stopped if the harddisk was saying it was >
> 32GB??) but the linux kernel correctly saw the right size.
> Looking ad the dmesg output right now I think that it is only seeing the
> smaller size.
> 
> sd 0:0:0:0: [sda] 66055248 512-byte hardware sectors (33820 MB)
> sd 0:0:0:0: [sda] Write Protect is off
> sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
> sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't
> support DPO
> 
> ibmsetmax output:
>  ./ibmsetmax /dev/sda
> Using device /dev/sda
> native max address: 66055247
> that is 33820286976 bytes, 33.8 GB
> lba capacity: 66055248 sectors (33820286976 bytes)
> 
> Is the clamping feature present in 2.6 by default? I cannot test this with
> a 2.4 kernel right now, since the libc no longer supports it. :)

Does libata.ignore_hpa=1 help?

-- 
tejun