HEADS UP: Check your devices' UDMA settings

[Basil Chupin]

It appears that Bug #195221 has suddenly come back -- see 
https://bugs.launchpad.net/ubuntu/+bug/195221.

This bug re-appeared on 1 April (my time, Australia, East Coast) because 
the previous day my logs showed that the UDMAs were being set correctly. 
The only thing which I can see is that on 1 April there was a kernel 
firmware upgrade but as I know nuffin' about kernels (or majors or even 
captains) this upgrade may have nothing to do with it.

What the above Bug is about is that even though your HDD, for example, 
can do UDMA 133 the UDMA in fact gets set to UDMA 33 because some check 
concludes incorrectly that the device is connected with a 40-wire cable. 
Here is an example I just took from my dmesg log file:

(the ata1 refers to the HDD/CDROM I have on the first PATA line and ata2 
refers to the HDD/DVDRW on line #2)

[    1.476324] ata1.00: ATA-8: WDC WD5000AAKB-00H8A0, 05.04E05, max 
UDMA/133 <=======XXXXXXXXXXXXX
[    1.476327] ata1.00: 976773168 sectors, multi 16: LBA48
[    1.476359] ata1.01: ATAPI: HL-DT-STDVD-ROM GDR8164B, 0L06, max 
UDMA/33 <=======XXXXXXXXXXXXX
[    1.476384] ata1: nv_mode_filter: 0x7f39f&0x7f39f->0x7f39f, 
BIOS=0x7f000 (0xc7c0c6c6) ACPI=0x7f01f (15:60:0x1f)
[    1.476391] ata1: nv_mode_filter: 0x739f&0x739f->0x739f, BIOS=0x7000 
(0xc7c0c6c6) ACPI=0x701f (15:60:0x1f)
[    1.492585] ata1.00: configured for UDMA/133 <=======XXXXXXXXXXXXX
[    1.508263] ata1.01: configured for UDMA/33 <=======XXXXXXXXXXXXX
......................................................

[    1.884316] ata2.00: HPA unlocked: 312579695 -> 312581808, native 
312581808
[    1.884322] ata2.00: ATA-7: ST3160215A, 3.AAD, max UDMA/100 
<========ZZZZZZZZZZZZ
[    1.884326] ata2.00: 312581808 sectors, multi 16: LBA48
[    1.884356] ata2.01: ATAPI: PIONEER DVD-RW  DVR-118L, 1.02, max 
UDMA/100 <========ZZZZZZZZZZZZ
[    1.884382] ata2: nv_mode_filter: 0x3f39f&0x3f39f->0x3f39f, 
BIOS=0x3f000 (0xc7c0c6c6) ACPI=0x3f01f (20:20:0x1f)
[    1.884386] ata2.00: limited to UDMA/33 due to 40-wire cable 
<========!!!!!!!!!!!!!!!!!!!!!
[    1.884391] ata2: nv_mode_filter: 0x3f39f&0x3f39f->0x3f39f, 
BIOS=0x3f000 (0xc7c0c6c6) ACPI=0x3f01f (20:20:0x1f)
[    1.884394] ata2.01: limited to UDMA/33 due to 40-wire cable 
<========!!!!!!!!!!!!!!!!!!!!!!
[    1.896098] firewire_core: created device fw0: GUID 00e0180000402cfe, 
S400
[    1.930139] ata2.00: configured for UDMA/33 <========@!@!@!@!@!@!
[    1.944263] ata2.01: configured for UDMA/33 <========@!@!@!@!@!@!
[    1.944792] scsi 1:0:0:0: Direct-Access     ATA      ST3160215A       
3.AA PQ: 0 ANSI: 5
[    1.944935] sd 1:0:0:0: Attached scsi generic sg2 type 0
[    1.947782] sd 1:0:0:0: [sdb] 312581808 512-byte logical blocks: (160 
GB/149 GiB)



Now, you may not be affected in this way but it would pay to check.

I haven't read all what is needed to fix this problem - there is a 
workaround but requires a patch, or something, to the kernel and I ain't 
too damn keen to do this considering that all was OK until beginning of 
1 April.

BC

-- 
Any experiment in life will be at your own experience.