2006/2/18, Alfredo Ferrari <list@pceet030.cern.ch>:

I have a Dell Precision M70 whose primary hard disk is a SATA disk
(/dev/sda) running FC4 (kernel 2.6.15-1.1831_FC4).
The secondary hard disk is a PATA one (/dev/hdc, in the laptop modular
bay) and apparently I cannot get DMA enabled on it, resulting in very poor
performances (2.5 MB/s against 25 MB/s for the same disk in the modular
bay of a PATA only Dell D800 where it runs happily with DMA enabled).

If I try to enable DMA by hand I get:

[root@pcalfr ~]# hdparm -d1 /dev/hdc

  setting using_dma to 1 (on)
  HDIO_SET_DMA failed: Operation not permitted
  using_dma    =  0 (off)

Every help/suggestion is greatly appreciated

              Alfredo Ferrari

P.S. The only messages of some relevance I can see at boot (from dmesg)

   DMA zone: 4096 pages, LIFO batch:0
   DMA32 zone: 0 pages, LIFO batch:0
   Normal zone: 225280 pages, LIFO batch:31
   HighMem zone: 294872 pages, LIFO batch:31


PCI: Ignoring BAR0-3 of IDE controller 0000:00:1f.2


Uniform Multi-Platform E-IDE driver Revision: 7.00alpha2
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
ide0: I/O resource 0x1F0-0x1F7 not free.
ide0: ports already in use, skipping probe
Probing IDE interface ide1...
hdc: ST94811A, ATA DISK drive
ide1 at 0x170-0x177,0x376 on irq 15
hdc: max request size: 1024KiB
hdc: 78140160 sectors (40007 MB) w/8192KiB Cache, CHS=16383/255/63
hdc: cache flushes supported
  hdc: hdc1 hdc2 hdc3 < hdc5 hdc6 hdc7 hdc8 >
ide-floppy driver 0.99.newide


SCSI subsystem initialized
libata version 1.20 loaded.
ata_piix 0000:00:1f.2: version 1.05
ACPI: PCI Interrupt 0000:00:1f.2[B] -> Link [LNKB] -> GSI 5 (level, low) -> IRQ 5
ata: 0x170 IDE port busy
PCI: Setting latency timer of device 0000:00: 1f.2 to 64
ata1: SATA max UDMA/133 cmd 0x1F0 ctl 0x3F6 bmdma 0xBFA0 irq 14
ata1: dev 0 cfg 49:0f00 82:746b 83:7fe9 84:4023 85:7469 86:3e49 87:4023 88:203f
ata1: dev 0 ATA-6, max UDMA/100, 195371568 sectors: LBA48
ata1(0): applying bridge limits
ata1: dev 0 configured for UDMA/100
scsi0 : ata_piix
   Vendor: ATA       Model: Hitachi HTS72101  Rev: MCZO
   Type:   Direct-Access                      ANSI SCSI revision: 05
SCSI device sda: 195371568 512-byte hdwr sectors (100030 MB)
SCSI device sda: drive cache: write back
SCSI device sda: 195371568 512-byte hdwr sectors (100030 MB)
SCSI device sda: drive cache: write back
  sda: sda1 sda2 sda3 sda4 < sda5 sda6 sda7<6>input: PS/2 Mouse as /class/input/input1
  sda8 sda9 >
sd 0:0:0:0: Attached scsi disk sda
input: AlpsPS/2 ALPS GlidePoint as /class/input/input2
kjournald starting.  Commit interval 600 seconds

Hi Alfredo,
is your PATA disk  attached to the secondary IDE channel? Not sure about laptop arch, but in desktop box primary and secondary IDE interface work different.

Alessandro Brezzi