LinuxQuestions.org - Dma & Udma

- Slackware (https://www.linuxquestions.org/questions/slackware-14/)

- - Dma & Udma (https://www.linuxquestions.org/questions/slackware-14/dma-and-udma-494726/)

I've had this problem on every Slackware install using the 2.4 kernel since I've started using Slackware. I get a message on boot that says my DMA is turned off and this may slow down fsck process. Normal I just build a 2.6 kernel with support for SMP and it goes away. For some reason I wanted to use the 2.4 kernel for a while this time but I hate seeing the above mentioned message.

Code:

/dev/hda:



 Model=HDT722525DLAT80, FwRev=V44OA70A, SerialNo=VDL41BT4DBA2TU

 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }

 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=51

 BuffType=DualPortCache, BuffSize=7674kB, MaxMultSect=16, MultSect=16

 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455

 IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}

 PIO modes:  pio0 pio1 pio2 pio3 pio4 

 DMA modes:  mdma0 mdma1 mdma2 

 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 

 AdvancedPM=yes: disabled (255) WriteCache=enabled

 Drive conforms to: ATA/ATAPI-7 T13 1532D revision 1:  ATA/ATAPI-2 ATA/ATAPI-3 ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7



 * signifies the current active mode

As I just posted above it looks like my harddrive supports UDMA and does not use the DMA mode. I guess I get that message because UDMA is what my drive supports.

Does a harddrive support both DMA & UDMA or do I have an issue that needs to be fixed ?

Can I make Slackware stop giving me the message if everything is ok?

Any help in explaining this would be great since I'm not hardware savvy.

Thanks.

UDMA is Ultra DMA, eh?

So as root maybe you can turn on DMA then put the line that works
for your box into /etc/rc.d/rc.local?

Yes, but why the message on boot ? Is there an option that needs to be built in the kernel on the 2.4.33.3. bareacpi.i kernel provided with slackware that was missed for my hardware or what ?
Here's some more info.

Code:

bash-3.1# hdparm -d1 /dev/hda



/dev/hda:

 setting using_dma to 1 (on)

 HDIO_SET_DMA failed: Operation not permitted

 using_dma    =  0 (off)

Also, the output on hdparm -Tt /dev/hda on this partition is
Timing cahed reads 1470.00 MB/Sec
Timing buffered disk reads: 2.80 MB/sec

compared to another partition on this same computer with a custom built kernel as:
Timing cach reads: 1467.69 MB/sec
Timing buffered disk reads: 66.57 MB/sec

As you can see the buffered disk is way off in speed.

Quote:

Originally Posted by davimint

Code:

/dev/hda:



 Model=HDT722525DLAT80, FwRev=V44OA70A, SerialNo=VDL41BT4DBA2TU

 Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }

 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=51

 BuffType=DualPortCache, BuffSize=7674kB, MaxMultSect=16, MultSect=16

 CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=268435455

 IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}

 PIO modes:  pio0 pio1 pio2 pio3 pio4 

 DMA modes:  mdma0 mdma1 mdma2 

 UDMA modes: udma0 udma1 udma2 udma3 udma4 udma5 *udma6 

 AdvancedPM=yes: disabled (255) WriteCache=enabled

 Drive conforms to: ATA/ATAPI-7 T13 1532D revision 1:  ATA/ATAPI-2 ATA/ATAPI-3 ATA/ATAPI-4 ATA/ATAPI-5 ATA/ATAPI-6 ATA/ATAPI-7



 * signifies the current active mode

Hi,

First, your drive showes that the support for all the displayed drive parameters of the hdparm. The * denotes the the active mode.

Man hdparm to understand the switches.

For the 'i' switch from 'man hdparm'

Quote:

-i Display the identification info that was obtained from the drive at boot time, if available. This is a feature of modern IDE drives, and may not be supported by older devices. The data returned may or may not be current, depending on activity since booting the system.

Code:

hardparm -I /dev/hda #get user friendly output

You should be able to understand this output better.

The 2.4.33 kernel supports most popular and standard ide, you might have to compile your own to use your ide controller if the problem persists.