Skip site navigation (1)Skip section navigation (2)
Date:      20 Apr 2000 12:25:33 -0400
From:      Arcady Genkin <a.genkin@utoronto.ca>
To:        freebsd-questions@FreeBSD.ORG
Subject:   Selectively enable/disable DMA for an ata driver
Message-ID:  <87og74d9j6.fsf@tea.thpoon.com>

next in thread | raw e-mail | index | archive | help
I have two HD: one supports DMA, the other doesn't. When I was running
3.4, I used to selectively turn on such features for each drive with
flags. Now it seems like there is only "options ATA_ENABLE_ATAPI_IDE",
which is global.

How would I work around that?

,----[ Currently I have ]
| device          ata0    at isa? port IO_WD1 irq 14 
| device          ata1    at isa? port IO_WD2 irq 15 
| device          ata 
| device          atadisk
| options         ATA_STATIC_ID           #Static device numbering
| options         ATA_ENABLE_ATAPI_DMA
`----
,----[ I used to have ]
| controller      wdc0    at isa? port "IO_WD1" bio irq 14 flags 0x90ff90ff 
| disk            wd0     at wdc0 drive 0 
| controller      wdc1    at isa? port "IO_WD2" bio irq 15 flags 0xb0ffb0ff 
| disk            wd2     at wdc1 drive 0
`----

It seems like both drives are initialized in DMA mode:
,----[ dmesg ]
| ad0: 2014MB <WDC AC22100H> [4092/16/63] at ata0-master using WDMA2
| ad2: 18366MB <QUANTUM BIGFOOT TS19.2A> [37317/16/63] at ata1-master using WDMA2
`----

I know for sure that ad0 does not support DMA, and has a habbit of
slowing down considerably if used with DMA (I remember from the time
when I experimented with different flags for the `wdc' driver).

Thanks for any insight!
-- 
Arcady Genkin                                 http://www.thpoon.com
Nostalgia isn't what it used to be.


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-questions" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?87og74d9j6.fsf>