SiI2112 + Seagate + nFroce2: no DMA!

Andre Hedrick wrote:

/>/
/>Seagate and Silicon Image are the only two player (well intel now) who did/ />their own PHY. They did not use the Marvel pairs./
/>/
/>It is a function of possible ECC on the wire and the relation to the/ />segments in the PIO or SG operations. It is a FIFO issue based on 512byte/ />boundaries being breached on corner cases./
/>/
/>The data on the wire is in 8K units./
/>/
/>It is a 7.5K + 0.5K corner case./
/>/
/>max_kb_per_request:15 == 7.5K/

/>/
/>This prevents this corner case until I can code the proper special case SG/ />table./
/>/
/>drive->id->hwconfig |= 0x6000;/
/>/
/>Is needed to fake the driver for device side cable detect./ />There are several issues and I have not had time to keep up./

-----Message d'origine-----
De : Emmanuel Hislen [mailto:[email protected]] Envoye : Saturday, January 24, 2004 1:27 AM A : Hugo Mills
Cc : [email protected]
Objet : RE: SiI2112 + Seagate + nFroce2: no DMA!

Hi Hugo,

I have re-installed my machine with Fedora Core 1 (thinking a newer version than RH9 would make the jump to 2.4.24 or 2.6 easier), and this fixed the DMA issue :-)

Now my SATA drive is running stable in UDMA6.

However, performance is still way below expectations.

I got a huge improvement: my disc read speed (hdparm -t) went from 1.3 to 25 MB/sec.
This is still slower than my PATA drive on my 3 years old AMD 900 PC running Redhat 9.0 (around 35 MB/sec).

Could you please let me know what you are getting so I know what to expect?

My next step is to try 2.4.24 or 2.6.1 as you suggested, but googling around a little bit before I do so I found out a few worrying things:

- people have reported a drop in performance on SATA in some 2.6 based kernel (2.6.0-test9), with reported speeds around 20MB/sec. Apparently there is no more way to tune max_kb_per_req in 2.6??
- I have found reports that both ide and libdata libraries are limiting max_kb_per_req to 15 Kb specifically for Seagate drives. So It looks like I can't even set it to 128 (I did not even try as I saw reports of memory corruption).

So basically since you've got it to work I'd like to know:

* what speed you get, and what is the RPM of your Seagate
* what is your max_kb_per_req setting (I have 15K)
* what is your accoustic management setting (I have 0)

I could not fix the time on linux so I am sending this mail from WinXP (just kidding I lost my mails on the linux machine after re-installing :-).

Thanks,

Emmanuel.

-----Message d'origine-----
De : Hugo Ranger Mills [mailto:[email protected]]De la part de Hugo Mills
Envoye : Tuesday, January 20, 2004 12:58 AM
A : manu
Cc : [email protected]
Objet : Re: SiI2112 + Seagate + nFroce2: no DMA!

On Tue, Dec 31, 2002 at 09:55:59PM -0800, manu wrote:

Incidentally, did you know that the date on your computer is very, very wrong?

Quoted 25 lines

I'm about to give up on my SATA drive as I can't get it to work properly. So I thought I may try asking the experts before falling back to PATA.

I have seen many mails reporting the same issue, some of them 6-month old:

- SATA drive comes up in pio mode, not in dma
- trying to turn on dma with hdparm is a nightmare: I/O errors, crash with data corruption... I tried both:

hddarm -d1 /dev/hde

and:

hdparm -u1 -c3 -d1 -X66 /dev/hde

crash in both cases :-((

Here's my equipment:

ABIT AN7 motherboard (nForce2 chipset, SiI3112 SATA controller) AMD Athlon XP 2600+ (+ 512 DDR / 400 MHz)
SATA HD Seagate Barracuda 160 Gb

Quoted 5 lines

The SATA HD is my only drive. The only thing connected to my IDE controllers is a DVD/CD combo.

Running Linux Redhat 9.0
kernel 2.4.20-28.9

^^^^^^^^^^^^^^^^^^
This is your problem. There have been a number of bug-fixes to the SiI drivers since 2.4.20. Try it again with a newer kernel -- such as 2.4.24.

Quoted 3 lines

I've been googling for days now and could not come accross a solution, on the contrary I came under the impression that the combination of SiI3112 +and Seagate was doomed.

Not so. I have a SiI3112 controller and a 120GiB Seagate drive, and they work very well together. I'm using 2.6.1, although 2.4.23 also worked well for me.

[snip]

Quoted 5 lines

Isn't there a solution??

I am willing to try patches of experimental code. At this point I am looking at reinstalling everything on a PATA drive anyway, so I have nothing to loose.

Try using 2.4.24 or 2.6.1.

Hugo.

--
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--- All hope abandon, Ye who press Enter here. ---

Hi again,

Here's a more complete report on this issue.

-1-

Going to Fedora Core 12.4.22-1.2115.nptl fixed the DMA issue. The Seagate SATA drive (ST3160023AS) came up in DMA mode.
The speed however (hdparm -t) was 25MB/s, better but still unacceptable.

I got the latest Fedora Core: 2.4.22-1.2149.nptl

Interestingly enough I found out that this release comes with a sata_sil module that is not even in 2.4.24, it was probably ported from 2.6.1 by the Fedora team.
Anyway I believe this is just a RAID driver, it did not change anything (same as -1-).

-5-

Now I tried kernel 2.6.1: it is worse, it dropped to 14 MB/s !?!?! I've seem several similar reports about 2.6.