With kernet 2.2.18 DMA mode for my harddisks worked just fine,
getting IDE DMA working on an AMD7409 controller with kernel 2.4.2 is a problem.
questions:
Why is DMA disabled on revision < C4?
How can I gat DMA working again?
The Information:
in 2.2.18 I get:
--------- dmesg: ----------
PCI_IDE: unknown IDE controller on PCI bus 00 device 39, VID=1022, DID=7409
PCI_IDE: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:DMA, hdb:pio
PCI_IDE: simplex device: DMA disabled
ide1: PCI_IDE Bus-Master DMA disabled (BIOS)
hda: IBM-DPTA-372050, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hda: IBM-DPTA-372050, 19574MB w/1961kB Cache, CHS=2495/255/63
---------------------------
hylke:/home/hylke# hdparm -v /dev/hda
/dev/hda:
multcount = 16 (on)
I/O support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 1 (on)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 2495/255/63, sectors = 40088160, start = 0
hylke:/home/hylke# hdparm -tT /dev/hda
/dev/hda:
Timing buffer-cache reads: 128 MB in 0.89 seconds =143.82 MB/sec
Timing buffered disk reads: 64 MB in 2.85 seconds = 22.46 MB/sec
----------------------------
All was fine.
I compiled 2.4.2, with:
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
CONFIG_BLK_DEV_IDEDMA_PCI=y
CONFIG_IDEDMA_PCI_AUTO=y
CONFIG_BLK_DEV_IDEDMA=y
CONFIG_IDEDMA_PCI_WIP=y
CONFIG_AMD7409_OVERRIDE=y
CONFIG_IDEDMA_AUTO=y
CONFIG_IDEDMA_IVB=y
and I get:
--------- dmesg: ----------
Uniform Multi-Platform E-IDE driver Revision: 6.31
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
AMD7409: IDE controller on PCI bus 00 dev 39
AMD7409: chipset revision 3
AMD7409: not 100% native mode: will probe irqs later
AMD7409: disabling single-word DMA support (revision < C4)
AMD7409: simplex device: DMA forced
ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:DMA, hdd:DMA
hda: IBM-DPTA-372050, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hda: 40088160 sectors (20525 MB) w/1961KiB Cache, CHS=2495/255/63
--------------------------
hylke:/home/hylke# hdparm -v /dev/hda
/dev/hda:
multcount = 16 (on)
I/O support = 1 (32-bit)
unmaskirq = 1 (on)
using_dma = 0 (off)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 2495/255/63, sectors = 40088160, start = 0
hylke:/home/hylke# hdparm -d1 /dev/hda
/dev/hda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma = 0 (off)
hylke:/home/hylke# hdparm -tT /dev/hda
/dev/hda:
Timing buffer-cache reads: 128 MB in 0.90 seconds =142.22 MB/sec
Timing buffered disk reads: 64 MB in 12.59 seconds = 5.08 MB/sec
-------------------------
My harddisk speed is down to 25%...
Greets,
Hylke van der Schaaf
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This archive was generated by hypermail 2b29 : Wed Mar 07 2001 - 21:00:09 EST