On Wednesday 24 January 2007 00:13, Tim Harvey wrote:
> --- Hans Verkuil <[EMAIL PROTECTED]> wrote:
> > On Tuesday 23 January 2007 22:35, Hans Verkuil wrote:
> > > On Tuesday 23 January 2007 20:05, Tim Harvey wrote:
> > > > Greetings,
> > > >
> > > > I'm running into a resource limit on my platform using ivtv and
> > > > its because the cx23416 pci device is requesting 64MB of PCI
> > > > memory space. Looking at
> > > > Documentation/video4linux/cx2341x/fw-memory.txt I don't see how
> > > > all this space is needed. Is there any problem with limiting
> > > > this window and if not is there a way within the linux kernel
> > > > to override the size resulting from the pci probe for a device?
> > >
> > > Urgh. I reduced the ioremap sizes, but completely forgot about
> > > the request_mem_region calls. I'm working on it now, expect a
> > > trunk commit soon.
> >
> > Committed. It now requests only a bit over 8MB for the cx23416 and
> > a bit over 16 MB for the cx23415. Please test, it should now work.
> >
> > Hans
>
> I most likely need this fix, however before the ITVT driver even
> loads I have an issue as the pci probe determines the device requests
> 64MB which the kernel reserves and then any other PCI devices found
> will fail to allocate resources appropriately - all before drivers
> are loaded. This basically means that on my platform the 'only' PCI
> device that I can have is the cx23416 based card unless I can figure
> out how to resolve this.
>
> So obviously my current issue isn't an ivtv driver issue, but perhaps
> someone here may be able to advise me how I can solve this.
>
> I couldn't figure out any way in the kernel to determine what the
> space a PCI device 'requested' was, so I added a line of debugging to
> my 2.6.19 kernel in drivers/pci/probe.c. Heres the applicable dmesg
> portions from my armeb IXP4xx platform:
>
> Linux version 2.6.19 ([EMAIL PROTECTED]) (gcc version 3.4.4) #23 Tue Jan
> 23 14:53:36 PST 2007
> CPU: XScale-IXP42x Family [690541f1] revision 1 (ARMv5TE),
> cr=000039ff Machine: Intel IXDP425 Development Platform
> Memory policy: ECC disabled, Data cache writeback
> CPU0: D VIVT undefined 5 cache
> CPU0: I cache: 32768 bytes, associativity 32, 32 byte lines, 32 sets
> CPU0: D cache: 32768 bytes, associativity 32, 32 byte lines, 32 sets
> Built 1 zonelists. Total pages: 16256
> Kernel command line: console=ttyS0,115200 root=/dev/ram0
> initrd=0x00800000,6M PID hash table entries: 256 (order: 8, 1024
> bytes)
> Dentry cache hash table entries: 8192 (order: 3, 32768 bytes)
> Inode-cache hash table entries: 4096 (order: 2, 16384 bytes)
> Memory: 64MB = 64MB total
> Memory: 56868KB available (1476K code, 303K data, 84K init)
> Mount-cache hash table entries: 512
> CPU: Testing write buffer coherency: ok
> checking if image is initramfs...it isn't (no cpio magic); looks like
> an initrd Freeing initrd memory: 6144K
> NET: Registered protocol family 16
> IXP4xx: Using 16MiB expansion bus window size
> PCI: IXP4xx is host
> PCI: IXP4xx Using direct access for memory space
> pci_read_bases: MEM dev=0000:00:01.0 168C:0013 pos=0 start=0x00000000
> end=0x0000ffff (size=65535)
> pci_read_bases: MEM dev=0000:00:02.0 4444:0016 pos=0 start=0xfc000000
> end=0xffffffff (size=67108863)
> pci_read_bases: MEM dev=0000:00:05.0 1131:1561 pos=0 start=0xfffff000
> end=0xffffffff (size=4095)
> pci_read_bases: MEM dev=0000:00:05.1 1131:1561 pos=0 start=0xfffff000
> end=0xffffffff (size=4095)
> pci_read_bases: MEM dev=0000:00:05.2 1131:1562 pos=0 start=0xffffff00
> end=0xffffffff (size=255)
> PCI: bus0: Fast back to back transfers disabled
> dmabounce: registered device 0000:00:01.0 on pci bus
> dmabounce: registered device 0000:00:02.0 on pci bus
> dmabounce: registered device 0000:00:05.0 on pci bus
> dmabounce: registered device 0000:00:05.1 on pci bus
> dmabounce: registered device 0000:00:05.2 on pci bus
> PCI: allocated mem resource #0:[EMAIL PROTECTED] for 0000:00:02.0
> 4444:0016 PCI: Failed to allocate mem resource #0:[EMAIL PROTECTED] for
> 0000:00:01.0 168C:0013
> PCI: Failed to allocate mem resource #0:[EMAIL PROTECTED] for
> 0000:00:05.0 1131:1561
> PCI: Failed to allocate mem resource #0:[EMAIL PROTECTED] for
> 0000:00:05.1 1131:1561
> PCI: Failed to allocate mem resource #0:[EMAIL PROTECTED] for 0000:00:05.2
> 1131:1562 NET: Registered protocol family 2
>
> You can see above that the cx23416 is requesting a PCI mem region of
> 64MB, which is the maximum region that the IXP4xx can provide,
> therefore the devices detected following that can't allocate their
> (meager) requirements. I'm assuming that the 'PCI: Failed to
> allocate mem resource' messages are indicative as the problem to
> follow where the device drivers fail to allocate their requested
> regions ('request_mem_region' fails for any driver other than ivtv as
> the cx23416 gobbled up all the space - even if the IVTV driver is
> never loaded)
>
> I've tried hacking around in drivers/pci/probe to reduce the memory
> size but I don't think I'm doing it correctly - is there some method
> in the kernel to override what a PCI device is asking for when
> probed?
Perhaps drivers/pci/quirks.c is a good place to look. These fixups are
called from pci_setup_device() in probe.c, so you might be able to do
something with it.
Hans
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