* [PATCH] Avoid PC(?) specific cascade dma reservation in kernel/dma.c
@ 2003-03-04 18:49 Johan Adolfsson
2003-03-04 22:53 ` Alan Cox
0 siblings, 1 reply; 3+ messages in thread
From: Johan Adolfsson @ 2003-03-04 18:49 UTC (permalink / raw)
To: Marcelo Tosatti, Linus Torvalds; +Cc: linux-kernel, Johan Adolfsson
I guess the reservation of dma channel 4 for "cascade" is
PC or chipset specific and we don't have such a thing in the
CRIS (ETRAX100LX) chip and channel 4 clashes with external dma0.
Perhaps a better fix is to #ifdef on something else or remove
the cascade stuff entirely from this file, but I leave that
to those who know better.
Have no other arch been bitten by this?
Please apply to both 2.4 and 2.5.
/Johan
diff -u -p -r1.3 dma.c
--- linux/kernel/dma.c 23 Feb 2001 13:50:32 -0000 1.3
+++ linux/kernel/dma.c 4 Mar 2003 18:46:51 -0000
@@ -59,7 +59,11 @@ static struct dma_chan dma_chan_busy[MAX
{ 0, 0 },
{ 0, 0 },
{ 0, 0 },
+#ifndef __CRIS__
{ 1, "cascade" },
+#else
+ { 0, 0 },
+#endif
{ 0, 0 },
{ 0, 0 },
{ 0, 0 }
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Avoid PC(?) specific cascade dma reservation in
2003-03-04 22:53 ` Alan Cox
@ 2003-03-04 22:00 ` John Bradford
0 siblings, 0 replies; 3+ messages in thread
From: John Bradford @ 2003-03-04 22:00 UTC (permalink / raw)
To: Alan Cox; +Cc: johan.adolfsson, marcelo, torvalds, linux-kernel
> > I guess the reservation of dma channel 4 for "cascade" is
> > PC or chipset specific and we don't have such a thing in the
> > CRIS (ETRAX100LX) chip and channel 4 clashes with external dma0.
> > Perhaps a better fix is to #ifdef on something else or remove
> > the cascade stuff entirely from this file, but I leave that
> > to those who know better.
> > Have no other arch been bitten by this?
>
> I don't know of any PC cards that can support ISA DMA channel 4
As far as I know, there is no pin defined for request or
acknowledgement of DMA channel 4 on the ISA bus - or am I missing
something?
John.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] Avoid PC(?) specific cascade dma reservation in kernel/dma.c
2003-03-04 18:49 [PATCH] Avoid PC(?) specific cascade dma reservation in kernel/dma.c Johan Adolfsson
@ 2003-03-04 22:53 ` Alan Cox
2003-03-04 22:00 ` [PATCH] Avoid PC(?) specific cascade dma reservation in John Bradford
0 siblings, 1 reply; 3+ messages in thread
From: Alan Cox @ 2003-03-04 22:53 UTC (permalink / raw)
To: Johan Adolfsson
Cc: Marcelo Tosatti, Linus Torvalds, Linux Kernel Mailing List
On Tue, 2003-03-04 at 18:49, Johan Adolfsson wrote:
> I guess the reservation of dma channel 4 for "cascade" is
> PC or chipset specific and we don't have such a thing in the
> CRIS (ETRAX100LX) chip and channel 4 clashes with external dma0.
> Perhaps a better fix is to #ifdef on something else or remove
> the cascade stuff entirely from this file, but I leave that
> to those who know better.
> Have no other arch been bitten by this?
I don't know of any PC cards that can support ISA DMA channel 4 so I
guess simply because of that it hasn't happened. Do you actually
know of any DMA 4 capable ISA devices or is it used for onboard
ISA devices ?
The ifdef is ugly. There should be a nicer way to do this.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2003-03-04 18:49 [PATCH] Avoid PC(?) specific cascade dma reservation in kernel/dma.c Johan Adolfsson
2003-03-04 22:53 ` Alan Cox
2003-03-04 22:00 ` [PATCH] Avoid PC(?) specific cascade dma reservation in John Bradford
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