Re: Audigy SE / ca0106 driver for PowerPC?

On Jan 31, 2007, at 4:27 PM, Russell McGuire wrote:

This makes sense...

So if I have setup in U-boot the PCI IO space to be at 0xf0300000  
and PCI
MOM space at 0x80000000 then the inl() command should be accessing the
0xf0300000 space? And the frame buffer is accessing the 0x80000000.

That's correct, however both of these will go through ioremap to get  
virtual addresses in the kernel.  For the IO space its done in the  
PCI setup code for the platform, and for MEM space its done by the  
driver.

The lock I experience, is when I compile the driver into the  
kernel. During
the PCI Probing, I have turned on ALL of the debug output, as well  
as placed
a ton of extra debug <printk> inside the ca0106 driver. I can see  
clearly
the kernel detects I have a sound card, as does it detect the video  
card.
Though I haven't gotten any PCI cards to function yet... The machine
literally just halts the boot cycle inside the first inl() command,  
and just
sits here until the reset button is pressed. It feels much like an  
illegal
access to a non-existant memory space <maybe that should be my clue  
= bus
hang?>

Ah, this we can debug :)

In arch/powerpc/kernel/pci_32.c enable DEBUG in the file (change the  
#undef DEBUG to #define DEBUG).  At which you'll get some output of  
the form.

Also, you can stick a few printk's in pci_process_bridge_OF_ranges 
().  I'd suggest one before:

	hose->io_base_virt = ioremap(ranges[na+2], size);

Perhaps then my problem lies in the OF_BLOB I am passing in to  
Linux? Could
this cause the problem? Is there a document someplace that  
describes the
<reg structure> passed into the kernel on the OF_BLOB for the PCI  
setup? I
made a good guess estimating this from other BLOB/dts files, but it is
possible I have some incorrect values.

That would cause problems if not setup correctly.  Look at  
Documentation/powerpc/booting-without-of.txt, however a quick glance  
doesn't seem to cover PCI.

You've given the start addresses for PCI MEM & PCI IO, can you tell  
me the sizes and I can help tell you want the node should look like.

- k

-----Original Message-----
From: Kumar Gala [mailto:galak@kernel.crashing.org]
Sent: Wednesday, January 31, 2007 1:55 PM
To: rmcguire@videopresence.com
Cc: linuxppc-embedded@ozlabs.org
Subject: Re: Audigy SE / ca0106 driver for PowerPC?


On Jan 31, 2007, at 3:00 PM, Russell McGuire wrote:

quoted

I am using the Freescale MPC8360E, with U-boot 1.2.0.
When I compile the kernel <2.6.20-rc6> I select the MPC8360E-MDS
board.
ARCH = PowerPC.

Well I might be all confused on the IO Remap, but if I look through
the
nvidafb driver and the ati frame buffer driver I can see the
resource_start() and pci_resource_len() function being called,
followed by
the ioremap() before any configuration is done with the PCI boards.

The difference is the nvidafb driver isn't doing PCI IO but PCI mem
accesses (note, I didn't see any inl/outl references in the nvida
driver).

quoted

The ca0106 driver seems to miss this <ioremap> function, and it is
the only
one that 100% locks the system up during the PCI probing <that I have
tried>, and it happens after/during the very first inl() or outl()
command.

This may be because IO space is setup properly.

When you say locks the system, what exactly happens?

quoted

I read a thread someplace that says that pci_resource_start() is not
intended to return an actual address, but rather a token that is to
be used
by the ioremap() function? It just happens that on some systems
this value
is the same and so for some it will not fail with a missing ioremap
(), but
others it will not be. To be safe it must be passed through ioremap
()? This
is the deprecated part, <right term? Perhaps just bad assumption is
a better
one> that this driver makes.

After looking through more drivers, this ioremap seems 100% in
place on my
drivers. Maybe nobody has tested this with PowerPC in the past?

ioremap() is intended for use with PCI MEM accesses not PCI IO.  If
you think about the fact that PCI IO is based on the x86 port IO
concept this makes sense.

quoted

See this thread as an example:
http://linux.derkeiler.com/Mailing-Lists/Kernel/2003-09/1187.html

Or see:
/drivers/video/nvidia/nvidia.c lines 1239->1243

Verses

/sound/pci/ca0106/ca0106_main.c
lines 1279 till the interrupt request
then lines 1069->1089 at which it locks on inl()

I don't mean to argue, I am just confused at this point.

Its ok.  I don't thinking you're arguing, just trying to figure out
what's going on.

- k