Subject: RE: Kunihiko Imais USB ohci driver doesn't work?

From: "Arjan Opmeer (EMN)" <[email-masked]>
Date: Mon, 28 Aug 2000 17:38:58 +0200

Hi,

> > He also mentioned a possible SA1111 DMA bug which would prevent USB
> > from working altogether. Does someone know whether Neponset can
> > suffer from this bug?
> 
> The bug is with the SA-1111; it would appear in any implementation.
> 
> See the SA-1111 specification update (June 2000), errata #7.

[ snip above 1MB memory DMA transfer problem ]

Yes, I heard about this one. But Kunihiko Imai seems to have spoken to
a circuit designer who told him that there was a problem with a SA1111
DMA line that "now" (?) should be fixed. The bug seems to interfere
with DMA bus mastering. He also says that he suffered from the bug for
a month... (and then probably had his hardware fixed?).

I am curious whether there really is a hardware problem with the
Neponset which would interfere with the USB driver. And if so which
revisions do have this symptom and how you can get your board fixed.

> This is necessary for my SAC patch as well, so if you'd like 
> to run with it, please keep in touch. =)

I am interested in anything that helps me use the USB port or the
Ethernet port on the SA1111 board. So keep me informed... ;)

Arjan

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---

From: Kunihiko IMAI <[email-masked]>
Date: Tue, 29 Aug 2000 13:52:42 +0900

Hello,

At Mon, 28 Aug 2000 17:38:58 +0200,

> a month... (and then probably had his hardware fixed?).

The problem which I wrote before is another problem.  It is
interconnection between SA1110 and SA1111.

The 6/30/00 errata of SA1111 has not fixed yet.  This bug exists
internal of SA1111 chip.

But the errata only points the POSSIBILITY of lost data.  So some
extent, DMA of SA1111 can work.

By the way do you fix usb-ohci-sa1111.h of my patch?  If you use with
neponset, this part:

#ifdef CONFIG_SA1100_XP860
#define PwrSensePolLow  1
#define PwrCtrlPolLow   1
#else
#define PwrSensePolLow  0
#define PwrCtrlPolLow   0
#endif

should be

#if defined(CONFIG_SA1100_XP860) || defined(CONFIG_ASSABET_NEPONSET)
#define PwrSensePolLow  1
#define PwrCtrlPolLow   1
#else
#define PwrSensePolLow  0
#define PwrCtrlPolLow   0
#endif

I compared schematics of XP860 and neponset, they has same polarity of 
these pins.
# The descriptions of these pins on SA1111 manual confuse us, I think.
# It should be written more clear.

Thanks.
_._. __._  _.. .  .___ ._. _____ _... ._ _._  _.._. .____  .__. ... .  _._

                                                             Kunihiko IMAI