Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
Blade 100 & DMA on IDE
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Gentoo on Sparc
View previous topic :: View next topic  
Author Message
smart
Guru
Guru


Joined: 19 Nov 2002
Posts: 455

PostPosted: Wed May 26, 2004 11:46 am    Post subject: Blade 100 & DMA on IDE Reply with quote

Hi there...

last state i was updated with is that using DMA for the IDE chipset on Blade 100 should be avoided due to incompatibilities possibly resulting in filesystem corruption... which i was able to verify from the backside of the coin.
Now in the sample config given on http://dev.gentoo.org/~ciaranm/configs/kernel/2.6.x/kernel-2.6.4-blade100.config.gz
that DMA is activated. Have i missed that the kernel been modified to support it since ?
Back to top
View user's profile Send private message
moocha
Watchman
Watchman


Joined: 21 Oct 2003
Posts: 5722
Location: Cluj-Napoca, Romania

PostPosted: Wed May 26, 2004 12:29 pm    Post subject: Reply with quote

Now, I don't have any experience with the SPARC architecture, but I may be able to help nevertheless.
From what I gather the Blade 100 uses the ALi 15x3 (actually M5229) ATA controller.
I used to have an x86 PC using the ALi Alladin V chipset that used the same controller. The controller revisions 0x20 and older indeed are said to contain some bugs - but it worked for years for me in UltraDMA Mode 2 (ATA33) without a hitch. Then the bug surfaced and ALi released the M1543C chipset (I presume C stands for Corrected *snicker*) and dropped any and all references to the original chipset from their site, pretending it never existed (they also refused to provide support, grr). Both ALi's Windows drivers and the Linux kernel driver dropped me into PIO mode (evil, CPU usage 100%). Hacking drivers/ide/pci/alim15x3.c to forcibly report UDMA capability allowed me to use UDMA just fine.
Lately it seems to have been confirmed that at least Multiword DMA mode 2 works fine - which is what I'm willing to bet the kernel's libata falls back to. Run
Code:
hdparm -i /dev/hda
(or whatever your device node may be) - that asterisk is probably next to mdma, not udma.
Run
Code:
lspci -v
and look for the M5229 controller revision in the output. From what I gathered from the driver source, revisions earlier than 0x20 can't do any DMA, 0x20 is supposed to be buggy and to be able to correctly do only MDMA mode 2 (but again, for me it worked in UDMA mode 2 for years without a single problem), 0xC0 is supposed to do UDMA mode 0 (it probably can do up to 2 at least, since it's newer than 0x20, but I don't know), and only revision 0xC4 and later know UDMA mode 5 (ATA100).
If you're interested, I can provide a patch to alim15x3.c that will let you use UDMA - but I'm not going to guarantee that your drive won't blow up and/or your cat won't get run over by a truck because of it :)
_________________
Military Commissions Act of 2006: http://tinyurl.com/jrcto

"Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety."
-- attributed to Benjamin Franklin
Back to top
View user's profile Send private message
smart
Guru
Guru


Joined: 19 Nov 2002
Posts: 455

PostPosted: Tue Jun 01, 2004 7:11 pm    Post subject: Reply with quote

Hi again,
thanks for the info. This is what i get from lspci...

0000:00:0d.0 IDE interface: ALi Corporation M5229 IDE (rev c3) (prog-if ff)
Flags: bus master, medium devsel, latency 64, IRQ 006eaf80
I/O ports at 0000000002000a00
I/O ports at 0000000002000a18 [size=4]
I/O ports at 0000000002000a10 [size=8]
I/O ports at 0000000002000a08 [size=4]
I/O ports at 0000000002000a20 [size=16]
Capabilities: [60] Power Management version 2

So my assumption using yourinfo would be that it *should* do DMA without problems ?
Back to top
View user's profile Send private message
moocha
Watchman
Watchman


Joined: 21 Oct 2003
Posts: 5722
Location: Cluj-Napoca, Romania

PostPosted: Tue Jun 01, 2004 7:56 pm    Post subject: Reply with quote

Yes. Revision 0xc3 (you have that) should do at least UDMA mode 2 without any trouble. However the kernel driver won't allow you to do that unless you modify it and tell it to not be so trusting of ALi's press releases.
_________________
Military Commissions Act of 2006: http://tinyurl.com/jrcto

"Those who would give up essential liberty to purchase a little temporary safety deserve neither liberty nor safety."
-- attributed to Benjamin Franklin
Back to top
View user's profile Send private message
smart
Guru
Guru


Joined: 19 Nov 2002
Posts: 455

PostPosted: Tue Jun 22, 2004 3:53 pm    Post subject: Reply with quote

Meanwhile, though i have not enabled DMA, disk access is fuckered up again. It seems to me something is seriously wrong, either with my machine, that disc or the drivers.
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Gentoo on Sparc All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum