Re: DMA is turned off on my HDD

[Anton Liaukevich <anthonyl@uvaga.by>]

Florian Kulzer wrote:
> On Mon, Jul 28, 2008 at 17:48:42 +0300, Anton Liaukevich wrote:
> > Florian Kulzer wrote:
> > > On Sun, Jul 27, 2008 at 23:05:15 +0300, Anton Liaukevich wrote:
> > > > Florian Kulzer wrote:
> > > > > On Sun, Jul 27, 2008 at 16:57:19 +0300, Anton Liaukevich wrote:
> > > > > > Florian Kulzer wrote:
> > > > > > > On Wed, Jul 23, 2008 at 20:59:09 +0300, Anton Liaukevich wrote:
> > > > > > > > Anton Liaukevich wrote:
> > > > > > > > > In several days I discovered that DMA is turned off on my 
> > > > > > > > > HDD (fsck  sayed it while Debian booting). Please, help me 
> > > > > > > > > turn on DMA mode.
> > > > > > > > >
> > > > > > > > > My hardware:
> > > > > > > > >     motherboard: Epox 8RDA3I rev 3.3 (nForce 2 Ultra)
> > > > > > > > >     hdd: WD1200JB (ide, 120gb)
> > > > > > > > >     cpu: Sempron 2200 (k7)
> > > > > [...]
> > I have tried command "dmesg | grep -Ei 'ata|ide|amd74xx'", suggested by  
> > you (after rebooting and logging in console (nor kdm that I use 
> > usually)).
> > Please read output in the attachment. Thank you for help.
>
> [...]
>
> > [    1.642452] Uniform Multi-Platform E-IDE driver
>
> OK, that seems to come from ide_core.
>
> > [    1.642530] ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
> > [    1.643173] Probing IDE interface ide0...
> > [    2.058474] hda: WDC WD1200JB-00EVA0, ATA DISK drive
> > [    2.730008] Probing IDE interface ide1...
> > [    3.592777] hdc: SONY CD-RW CRX320E, ATAPI CD/DVD-ROM drive
> > [    4.264276] ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
> > [    4.264276] ide1 at 0x170-0x177,0x376 on irq 15
> > [   13.612015] hdc: ATAPI 52X DVD-ROM CD-R/RW drive, 2048kB Cache
>
> Some driver (ide_generic?) takes control of the devices before libata is
> loaded. Check the output of "cat /proc/interrupts" to see which module
> has IRQs 14 and 15.
>
> > [   14.218581] libata version 3.00 loaded.
> > [   14.740018] NFORCE2: IDE controller (0x10de:0x0065 rev 0xa2) at  PCI slot 0000:00:09.0
> > [   14.740306] NFORCE2: port 0x01f0 already claimed by ide0
> > [   14.740378] NFORCE2: port 0x0170 already claimed by ide1
>
> The nforce2 driver cannot take ove rthe devices => no DMA.
>
> I can think of a few more things to try, but I don't know how "safe"
> they are:
>
> - put amd74xx as the first non-comment line into /etc/modules
>
> - boot with "blacklist=ide_generic" appended to the kernel command line
>
> - likewise, try "libata.dma=3" at boot (may be dangerous)
>
> - check the kernel documentation for "libata.force=..." (can be really
>   dangerous)
>
> - check if the amd74xx module is included in your initrd:
>   zcat /boot/initrd.img-$(uname -r) | cpio --quiet -t | grep -E '(ide|ata|amd)[^/]*\.ko'
>
> - build your own kernel with amd74xx compiled in
I'm giving you contents of '/proc/interrupts' file:

anthony@leva:~$ cat /proc/interrupts
           CPU0
  0:         66   IO-APIC-edge      timer
  1:       2570   IO-APIC-edge      i8042
  3:          2   IO-APIC-edge
  4:          2   IO-APIC-edge
  6:          5   IO-APIC-edge      floppy
  7:          0   IO-APIC-edge      parport0
  8:          2   IO-APIC-edge      rtc0
  9:          0   IO-APIC-fasteoi   acpi
 10:          0   IO-APIC-edge      MPU401 UART
 12:     100951   IO-APIC-edge      i8042
 14:     604231   IO-APIC-edge      ide0
 15:      20161   IO-APIC-edge      ide1
 17:        742   IO-APIC-fasteoi   eth1
 20:          0   IO-APIC-fasteoi   ohci_hcd:usb2
 21:       4317   IO-APIC-fasteoi   ehci_hcd:usb1, NVidia nForce2
 22:          0   IO-APIC-fasteoi   ohci_hcd:usb3
NMI:          0   Non-maskable interrupts
LOC:     117665   Local timer interrupts
RES:          0   Rescheduling interrupts
CAL:          0   function call interrupts
TLB:          0   TLB shootdowns
TRM:          0   Thermal event interrupts
SPU:          0   Spurious interrupts
ERR:          0
MIS:          0

I'm novice in Linux and I don't know how to see which module
has IRQs 14 and 15. Commands "lsmod | grep '604231|20161'" & "ps -A | 
grep '604231|20161'" output nothing. Moreover I have noticed that 
numbers in the second column of 'cat /proc/interrupts' output sometimes 
changes (I have been running it several times). Unfortunately, I haven't 
found in man any documentation about '/proc/interrupts' file format.