New PCMCIA

[Pavel Roskin]

On Fri, 11 Apr 2003, Dominik Brodowski wrote:

> > ... and it was the first message to the list.
>
> Really? IIRC there was a test message to the list by dwmw before I
> subscribed, and I sent one to the list, too :)

Look for yourself:
http://lists.infradead.org/pipermail/linux-pcmcia/

Maybe you mean a mailing list on SourceForge?  There was a project there.
The CVS repository had something like 4 files.  I cannot find that project
anymore.

By the way, we really need CVS for the project.  Maybe it should be
another project on Sourceforge?

> > We could also "cripple" yenta_socket and disable remapping of resources.
> > That would be useful for fixing client drivers.
>
> /me has (almost) no idea about PCMCIA resource handling yet, that's
> Russell's call to make :)

As I understand it, pcmcia_core requests the socket driver to provide a
window (memory or I/O) is a certain region to the given resource.  The
socket driver is not supposed to own that resource (unless it indicates
that it has a static map, but most "normal" sockets don't).  Then
pcmcia_core reserves the resource and gives it to the client driver.

Although it's possible to request the existing mapping from the socket
driver, this code is not used.  pcmcia_core essentially assumes that its
requests are always satisfied.

For example, plx9052 can provide a 0x40 bytes long I/O window in the
region is already owns as a PCI resource.  In my case, it's
0xc000-0xc003f.  pcnet_cs wants to get an I/O resource at 0x300.
pcmcia_core notices that plx9052 has a fixed I/O window (thanks for that,
David Hinds' pcmcia-cs doesn't support io_offset at all) in
alloc_io_space() and guess what it does?

It removes bits 12 and above from the address by ANDing it with 0x0fff,
wrongly assuming that every driver can remap its I/O space withing 4k
after the base address.  Then it "extends" (!!!) the window and gives the
driver a window at 0xc300.  Not only is this region not allocated by the
socket driver, but the socket driver refuses to relocate the resource
there.  It's outrageous!

> > Thank you for this information.  I think I'll start with making the
> > plx9052 driver work with pcnet_cs and ide-cs.  I also want to remove
> > timers from the drivers I can test.
>
> That's great! Thanks!

Can I have CVS access for those drivers?  I also would like to work on the
orinoco driver, because I know it very well, and because I have already
done some work on improving it's PCMCIA interface.  I'm not going to do
any architecture changes without your approval.

-- 
Regards,
Pavel Roskin