[PATCH] Driver for FECs on motorola DUET (87x/88x)

[PATCH] Driver for FECs on motorola DUET (87x/88x)

[Pantelis Antoniou]

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Hello

The attached patch is a driver for both the FECs on the new
motorola 87x/88x processors.

I first tried to modified the old FEC driver but due to hardware
peculiarities and the large modification needed I decided to
create a new driver based on the old one.

The main features of the driver are:

o Supports correctly both FECs.
o Easier way to add new boards.
o MII ethtool support.
o NAPI support.
o Support polling mode of link changes even with
  generic phys.
o No fixed receive ethernet buffers zero copy receive,
  based on the work of Joakim Tjernlund.
o Copy small received frames to reduce memory consumption.
o I think it will be easier to port to 2.6. Haven't yet a
  chance to try it though.

The major changes were:

o Moved location to drivers/net
o It is now a whole subdirectory instead of just one file.
o MII no longer interrupt driven.

Note that the board which uses it is not in the tree
since it depends on other patches that were rejected for 2.4.
However it is trivial to add more boards.

Please take a look and comment.

Regards

Pantelis


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RE: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Joakim Tjernlund]

> Hi there,
>
> After our little talk in IRC I've ported the driver to 2.6
> and have gotten as far as the loading of init (which promptly crashes).
>
> I think I am very near to making it work...
>
> I have a BDI2000 and I'm not afraid to use it, but I don't know
> what to look for?
>
> Any mm hackers over there have any idea?

To start with, I think you should fix the Machine Check
exception in head_8xx.S to get proper error reporting.
I think it should be:
	. = 0x200
MachineCheck:
 	EXCEPTION_PROLOG
 	mfspr	r4,DAR
 	stw	r4,_DAR(r11)
 	mfspr	r5,DSISR
 	stw	r5,_DSISR(r11)
 	addi	r3,r1,STACK_FRAME_OVERHEAD
 	EXC_XFER_EE(0x200, MachineCheckException)

Does init crash or just hang?
If it hangs, it may be a TLB problem.


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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Pantelis Antoniou]

Joakim Tjernlund wrote:

>>Hi there,
>>
>>After our little talk in IRC I've ported the driver to 2.6
>>and have gotten as far as the loading of init (which promptly crashes).
>>
>>I think I am very near to making it work...
>>
>>I have a BDI2000 and I'm not afraid to use it, but I don't know
>>what to look for?
>>
>>Any mm hackers over there have any idea?
>>
>
>To start with, I think you should fix the Machine Check
>exception in head_8xx.S to get proper error reporting.
>I think it should be:
>	. = 0x200
>MachineCheck:
> 	EXCEPTION_PROLOG
> 	mfspr	r4,DAR
> 	stw	r4,_DAR(r11)
> 	mfspr	r5,DSISR
> 	stw	r5,_DSISR(r11)
> 	addi	r3,r1,STACK_FRAME_OVERHEAD
> 	EXC_XFER_EE(0x200, MachineCheckException)
>
>Does init crash or just hang?
>If it hangs, it may be a TLB problem.
>
>
>
>
It crashes and the backtrace seems sane.

Regards

Pantelis


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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Pantelis Antoniou]

Progress report.

Got it to move even further.

No longer crashes but it seems stuck in something related
to the serial console.

Still responds to pings, so I'm very hopefull.

Come Monday I'll probably get it to work...

Regards

Pantelis


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RE: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Joakim Tjernlund]

> From: Pantelis Antoniou [mailto:panto@intracom.gr]
>
> Progress report.
>
> Got it to move even further.

Great!

>
> No longer crashes but it seems stuck in something related
> to the serial console.

If you are going to mess with the 8xx_io/uart.c, you might
want to port this from 2.4:
http://ppc.bkbits.net:8080/linuxppc-2.4/diffs/arch/ppc/8xx_io/uart.c@1.14.1.9?nav=index.html|src/.|src/arch|src/arch/ppc|src/arch/pp
c/8xx_io|hist/arch/ppc/8xx_io/uart.c


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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Pantelis Antoniou]

Joakim Tjernlund wrote:

>>From: Pantelis Antoniou [mailto:panto@intracom.gr]
>>
>>Progress report.
>>
>>Got it to move even further.
>>
>
>Great!
>
>
:P

>>No longer crashes but it seems stuck in something related
>>to the serial console.
>>
>
>If you are going to mess with the 8xx_io/uart.c, you might
>want to port this from 2.4:
>http://ppc.bkbits.net:8080/linuxppc-2.4/diffs/arch/ppc/8xx_io/uart.c@1.14.1.9?nav=index.html|src/.|src/arch|src/arch/ppc|src/arch/pp
>c/8xx_io|hist/arch/ppc/8xx_io/uart.c
>
>
>
>
I know, I tried to port it over but it's a mess.
Things have changed dramatically in the serial subsystem in 2.6.

I'm not sure that I will avoid rewritting the serial driver.

Regards

Pantelis


Regards

Pantelis


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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Tom Rini]

On Fri, May 14, 2004 at 05:23:20PM +0200, Joakim Tjernlund wrote:

> > From: Pantelis Antoniou [mailto:panto@intracom.gr]
> >
> > Progress report.
> >
> > Got it to move even further.
>
> Great!
>
> >
> > No longer crashes but it seems stuck in something related
> > to the serial console.
>
> If you are going to mess with the 8xx_io/uart.c, you might
> want to port this from 2.4:
> http://ppc.bkbits.net:8080/linuxppc-2.4/diffs/arch/ppc/8xx_io/uart.c@1.14.1.9?nav=index.html|src/.|src/arch|src/arch/ppc|src/arch/pp
> c/8xx_io|hist/arch/ppc/8xx_io/uart.c

I'd prefer asking Kumar Gala for the re-written serial driver he did for
cpm2, and either copying that and making it work for cpm1 (8xx) or
adding cpm1 support cleanly into it.  I can provide an older, but
working on some variant of 2.4, serial driver vs the drivers/serial
infrastructure as well, if needed (I didn't write it, fwiw).

--
Tom Rini
http://gate.crashing.org/~trini/

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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Dan Malek]

On May 14, 2004, at 8:49 AM, Pantelis Antoniou wrote:

> Any mm hackers over there have any idea?

I have some ideas.  There are some "generic" functions
doing some lazy processing that isn't likely to be valid
on the 8xx, in particular the way demand zero pages
are handled.  Anyway, that's as far as I've traced it.
Sometimes it appears to work, but it could be that what
is happening still isn't correct, it just doesn't crash/hang.
There are few other things that caught my attention where
we used to execute generic PPC MM code without any
ill side effects, but when these were ported to 2.6 we
are now doing the wrong things on the 8xx.  We just have
to work our way though it with some applications and
testing.

	-- Dan


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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Pantelis Antoniou]

Dan Malek wrote:

>
> On May 14, 2004, at 8:49 AM, Pantelis Antoniou wrote:
>
>> Any mm hackers over there have any idea?
>
>
> I have some ideas.  There are some "generic" functions
> doing some lazy processing that isn't likely to be valid
> on the 8xx, in particular the way demand zero pages
> are handled.  Anyway, that's as far as I've traced it.
> Sometimes it appears to work, but it could be that what
> is happening still isn't correct, it just doesn't crash/hang.
> There are few other things that caught my attention where
> we used to execute generic PPC MM code without any
> ill side effects, but when these were ported to 2.6 we
> are now doing the wrong things on the 8xx.  We just have
> to work our way though it with some applications and
> testing.

I have made some progress...

I have ported the CPM UART driver by Kumar Gala to the 8xx.

It works correctly but still the same problem persists...

It correctly mounts the NFS root, and after the first write
by init it hangs.

By breaking in using my BDI2000 I see it stuck at default_idle.

Networking & interrupts appear OK, since I can still ping.

It seems that for some reason no user space scheduling takes place.

Apparently the scheduling is controlled by the _TIF_NEED_RESCHED
flag which is no where to be found in head_8xx.S.

Before I submerge into the assembly of head_8xx.S does anyone have any
ideas?

>
>     -- Dan
>
>
Regards

Pantelis


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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Dan Malek]

On May 24, 2004, at 9:40 AM, Pantelis Antoniou wrote:

> Before I submerge into the assembly of head_8xx.S does anyone have any
> ideas?

I just used head.S, which works fine on the 82xx, as a model for the
code in head_8xx.S.  I've been looking at some "common" PPC cache
management functions that I'm not certain are doing the proper thing
on the 8xx.  I'm suspecting some data corruption problems due to
improper effects of cache instructions.

There are some optimizations we can do to head_8xx.S, but I don't
think there is anything incorrect in it.


	-- Dan


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RE: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Joakim Tjernlund]

> I just used head.S, which works fine on the 82xx, as a model for the
> code in head_8xx.S.  I've been looking at some "common" PPC cache
> management functions that I'm not certain are doing the proper thing
> on the 8xx.  I'm suspecting some data corruption problems due to
> improper effects of cache instructions.
>
> There are some optimizations we can do to head_8xx.S, but I don't
> think there is anything incorrect in it.

I do think there is something wrong in head_8xx.S. Check
http://lists.linuxppc.org/linuxppc-embedded/200405/msg00109.html
for details.


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Re: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Paul Mackerras]

Dan Malek writes:

> There are some optimizations we can do to head_8xx.S, but I don't
> think there is anything incorrect in it.

Given that the 860 manual says that the 860 sets DAR and DSISR on a
machine check, I think Joakim's patch is desirable.  I assume other
8xx processors do also.

Paul.

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RE: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Joakim Tjernlund]

> Given that the 860 manual says that the 860 sets DAR and DSISR on a
> machine check, I think Joakim's patch is desirable.  I assume other
> 8xx processors do also.
>
> Paul.

I wonder if this applies to head.S also? I don't have a manual
handy, but since the Alignment exceptions are identical, I guess
that DAR & DSISR are also set for the CPUs that uses head.S?

Currently only 8xx uses these in the machine check exception, but I
think the these registers should be accurate. They may be useful for
debugging if nothing else.

 Jocke


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RE: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Paul Mackerras]

Joakim Tjernlund writes:

> I wonder if this applies to head.S also? I don't have a manual
> handy, but since the Alignment exceptions are identical, I guess
> that DAR & DSISR are also set for the CPUs that uses head.S?

No, the 6xx/7xx/7xxx processors only set SRR0/1 on a machine check.

Paul.

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Re: 2.6 on 8xx (was [PATCH] Driver for FECs on motorola DUET (87x/88x))

[Robert P. J. Day]

On Tue, 25 May 2004, Pantelis Antoniou wrote:

> Hi there
>
> Success!!!
>
>   netvia-ppc root # uname -a
>   Linux netvia-ppc 2.6.6 #54 Tue May 25 13:53:27 EEST 2004 ppc ppc ppc
> GNU/Linux
>
> Everything works now, the problem was with the uart driver, had a
> problem with
> the interrupts.

i'm definitely interested in what it took for you to get this to work.
currently, i've got a perfectly working system, booting a 2.4-based
kernel, compiled with ELDK 3.0, on a customized 8xx board.  this system
uses the now-deprecated "devfs".

i bk-cloned the linuxppc-2.5 tree, did "make menuconfig" as best i could
(guessing every so often at some of the new features), compiled a new
kernel and, glory be, actually got the new kernel to boot up to the point
of trying to start "init", at which point it hung.

i'm using embedded planet's planet core bootloader and, although i'd love
to make the switch to u-boot, given that planet core seems to be doing the
job at the moment, i think i won't tempt the gods just yet.  that's a
later project.

given that "devfs" is now technically obsolete, i'm wondering what you did
in terms of the kernel configuration, and what you had to do in your root
filesystem to effect the switch over to (i'm assuming) sysfs+udev.

mind sharing your .config file for this?  i'm not interested in getting
every feature of this board to work at the moment -- just getting to the
command line prompt would make me happy.

rday


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Re: 2.6 on 8xx (was [PATCH] Driver for FECs on motorola DUET (87x/88x))

[Pantelis Antoniou]

Robert P. J. Day wrote:

>On Tue, 25 May 2004, Pantelis Antoniou wrote:
>
>
>>Hi there
>>
>>Success!!!
>>
>>  netvia-ppc root # uname -a
>>  Linux netvia-ppc 2.6.6 #54 Tue May 25 13:53:27 EEST 2004 ppc ppc ppc
>>GNU/Linux
>>
>>Everything works now, the problem was with the uart driver, had a
>>problem with
>>the interrupts.
>>
>
>i'm definitely interested in what it took for you to get this to work.
>currently, i've got a perfectly working system, booting a 2.4-based
>kernel, compiled with ELDK 3.0, on a customized 8xx board.  this system
>uses the now-deprecated "devfs".
>
I used an NFS mounted root ELDK 3.0 filesystem. By mistake I booted with
devfs and everything worked except the telnet networked logins.
Did not have time to check why though.

>
>i bk-cloned the linuxppc-2.5 tree, did "make menuconfig" as best i could
>(guessing every so often at some of the new features), compiled a new
>kernel and, glory be, actually got the new kernel to boot up to the point
>of trying to start "init", at which point it hung.
>
Well you wont get any further than this using the stock kernel.

I had to use my own ethernet and a ported over serial uart driver for CPM2
boards.

Also some tweaking is needed to the irq dispatch and defining out
some mmu staff which do not apply for 8xx.

>
>i'm using embedded planet's planet core bootloader and, although i'd love
>to make the switch to u-boot, given that planet core seems to be doing the
>job at the moment, i think i won't tempt the gods just yet.  that's a
>later project.
>
>
My condolences :)

>given that "devfs" is now technically obsolete, i'm wondering what you did
>in terms of the kernel configuration, and what you had to do in your root
>filesystem to effect the switch over to (i'm assuming) sysfs+udev.
>
I did nothing special; it appeared to just work.

>
>mind sharing your .config file for this?  i'm not interested in getting
>every feature of this board to work at the moment -- just getting to the
>command line prompt would make me happy.
>
Patience, I'll clean the stuff up and post them here.

>
>rday
>
>
>
>
Regards

Pantelis


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Re: 2.6 on 8xx (was [PATCH] Driver for FECs on motorola DUET (87x/88x))

[Robert P. J. Day]

On Tue, 25 May 2004, Pantelis Antoniou wrote:

>
> Robert P. J. Day wrote:

> >i'm definitely interested in what it took for you to get this to work.
> >currently, i've got a perfectly working system, booting a 2.4-based
> >kernel, compiled with ELDK 3.0, on a customized 8xx board.  this system
> >uses the now-deprecated "devfs".
> >
> I used an NFS mounted root ELDK 3.0 filesystem. By mistake I booted with
> devfs and everything worked except the telnet networked logins.
> Did not have time to check why though.

oh, so devfs, although deprecated, will still work?  that's good to know,
one less thing i need to fight with.

> >i bk-cloned the linuxppc-2.5 tree, did "make menuconfig" as best i could
> >(guessing every so often at some of the new features), compiled a new
> >kernel and, glory be, actually got the new kernel to boot up to the point
> >of trying to start "init", at which point it hung.
> >
> Well you wont get any further than this using the stock kernel.
>
> I had to use my own ethernet and a ported over serial uart driver for CPM2
> boards.
>
> Also some tweaking is needed to the irq dispatch and defining out
> some mmu staff which do not apply for 8xx.

ok, i'll just hang out and wait for changes to eventually appear.  no
big rush on my part.  thanks.

rday

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RE: [PATCH] Driver for FECs on motorola DUET (87x/88x)

[Joakim Tjernlund]

> On May 24, 2004, at 3:11 PM, Joakim Tjernlund wrote:
>
> > I do think there is something wrong in head_8xx.S. Check
> > http://lists.linuxppc.org/linuxppc-embedded/200405/msg00109.html
> > for details.
>
> Yes, that should be there but it doesn't prevent normal operation.
> It just causes a fatal error to print helpful information.

.. which is why I keep bugging you to add it. Useful error reporting
while debugging is a Good Thing.

 Jocke


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