Re: via82cxxx, DMA and performance problem

[shal <shal@free.fr>]

Bartlomiej Zolnierkiewicz wrote:
> Hi,
> 
> You trying to load VIA IDE chipset driver but your IDE devices
> are already handled by generic IDE driver, thus you can't enable DMA.
> 
> Changing host drivers on the fly is unsupported.
> 
> If you want to use IDE chipset modules you should use IDE as module.

Ok thank you for your response.

I have included in the kernel the via82cxxx support.

Now when I boot , it was very slow and I have this :

ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
VP_IDE: IDE controller at PCI slot 0000:00:11.1
ACPI: No IRQ known for interrupt pin A of device 0000:00:11.1 - using 
IRQ 255
VP_IDE: chipset revision 6
VP_IDE: not 100% native mode: will probe irqs later
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
VP_IDE: VIA vt8235 (rev 00) IDE UDMA133 controller on pci0000:00:11.1
     ide0: BM-DMA at 0xfc00-0xfc07, BIOS settings: hda:DMA, hdb:DMA
     ide1: BM-DMA at 0xfc08-0xfc0f, BIOS settings: hdc:DMA, hdd:pio
hda: MAXTOR 6L040J2, ATA DISK drive
hdb: Maxtor 83240D3, ATA DISK drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hdc: CRD-8322B, ATAPI CD/DVD-ROM drive
ide1 at 0x170-0x177,0x376 on irq 15
hda: max request size: 128KiB
hda: 78177792 sectors (40027 MB) w/1819KiB Cache, CHS=65535/16/63, UDMA(133)
  hda:<4>hda: dma_timer_expiry: dma status == 0x61
hda: DMA timeout error
hda: dma timeout error: status=0x58 { DriveReady SeekComplete DataRequest }

  hda1 hda2 <<4>hda: dma_timer_expiry: dma status == 0x61
hda: DMA timeout error
hda: dma timeout error: status=0x58 { DriveReady SeekComplete DataRequest }

  hda5<4>hda: dma_timer_expiry: dma status == 0x61
hda: DMA timeout error
hda: dma timeout error: status=0x58 { DriveReady SeekComplete DataRequest }

  hda6 hda7<4>hda: dma_timer_expiry: dma status == 0x61
hda: DMA timeout error
hda: dma timeout error: status=0x58 { DriveReady SeekComplete DataRequest }

  hda8 > hda3
hdb: max request size: 128KiB
hdb: 6329388 sectors (3240 MB) w/256KiB Cache, CHS=6697/15/63, UDMA(33)
  hdb: hdb1 hdb2
hdc: ATAPI 32X CD-ROM drive, 128kB Cache, DMA
Uniform CD-ROM driver Revision: 3.12


Each dma_timer_expiry is long.


I have this at boot :
# hdparm /dev/hda
/dev/hda:
  multcount    = 16 (on)
  IO_support   =  1 (32-bit)
  unmaskirq    =  1 (on)
  using_dma    =  0 (off)
  keepsettings =  0 (off)
  readonly     =  0 (off)
  readahead    = 256 (on)
  geometry     = 65535/16/63, sectors = 78177792, start = 0
# hdparm -tT /dev/hda
/dev/hda:
  Timing buffer-cache reads:   924 MB in  2.01 seconds = 460.46 MB/sec
  Timing buffered disk reads:   20 MB in  3.08 seconds =   6.50 MB/sec



When active dma the disk access freeze during a long time and I have 
this error :
hda: dma_timer_expiry: dma status == 0x61
hda: DMA timeout error
hda: dma timeout error: status=0x58 { DriveReady SeekComplete DataRequest }

and the performance is the same :
# hdparm -tT /dev/hda
/dev/hda:
  Timing buffer-cache reads:   948 MB in  2.01 seconds = 472.42 MB/sec
  Timing buffered disk reads:   20 MB in  3.08 seconds =   6.50 MB/sec


This is a part of my .config:
#
# IDE chipset support/bugfixes
#
# CONFIG_BLK_DEV_CMD640 is not set
# CONFIG_BLK_DEV_IDEPNP is not set
CONFIG_BLK_DEV_IDEPCI=y
CONFIG_IDEPCI_SHARE_IRQ=y
# CONFIG_BLK_DEV_OFFBOARD is not set
# CONFIG_BLK_DEV_GENERIC is not set
# CONFIG_BLK_DEV_OPTI621 is not set
# CONFIG_BLK_DEV_RZ1000 is not set
CONFIG_BLK_DEV_IDEDMA_PCI=y
# CONFIG_BLK_DEV_IDEDMA_FORCED is not set
CONFIG_IDEDMA_PCI_AUTO=y
# CONFIG_IDEDMA_ONLYDISK is not set
# CONFIG_IDEDMA_PCI_WIP is not set
CONFIG_BLK_DEV_ADMA=y
# CONFIG_BLK_DEV_AEC62XX is not set
# CONFIG_BLK_DEV_ALI15X3 is not set
# CONFIG_BLK_DEV_AMD74XX is not set
# CONFIG_BLK_DEV_CMD64X is not set
# CONFIG_BLK_DEV_TRIFLEX is not set
# CONFIG_BLK_DEV_CY82C693 is not set
# CONFIG_BLK_DEV_CS5520 is not set
# CONFIG_BLK_DEV_CS5530 is not set
# CONFIG_BLK_DEV_HPT34X is not set
# CONFIG_BLK_DEV_HPT366 is not set
# CONFIG_BLK_DEV_SC1200 is not set
CONFIG_BLK_DEV_PIIX=y
# CONFIG_BLK_DEV_NS87415 is not set
# CONFIG_BLK_DEV_PDC202XX_OLD is not set
# CONFIG_BLK_DEV_PDC202XX_NEW is not set
# CONFIG_BLK_DEV_SVWKS is not set
# CONFIG_BLK_DEV_SIIMAGE is not set
# CONFIG_BLK_DEV_SIS5513 is not set
# CONFIG_BLK_DEV_SLC90E66 is not set
# CONFIG_BLK_DEV_TRM290 is not set
CONFIG_BLK_DEV_VIA82CXXX=y
CONFIG_BLK_DEV_IDEDMA=y
# CONFIG_IDEDMA_IVB is not set
CONFIG_IDEDMA_AUTO=y
# CONFIG_DMA_NONPCI is not set
# CONFIG_BLK_DEV_HD is not set