PCI: device not available (can't reserve [mem 0x00000000-0x0003ffff])

ramukaka · 09-01-2010, 10:13 AM

Hi,

I am facing a strange problem with a PCI express device. I have written a simple PCI driver(pci_skel sample driver for LDD book) just to detect a PCI device and read its vender and device id from its configuration space. When I connect the device on a standard i386 based PC, it works fine, as expected. But when I run the same driver on the MPC837xERDB board(powerpc arch based processor from freescale), it gives me error. Below is the O/P on both the architectures. Could anyone suggest what can be the cause of this problem? I am new to linux device driver development.

i386 output.

Quote:

[ 921.097050] PCI driver: Init function
[ 921.097415] PCI driver: Probe function
[ 921.097442] pci_skel 0000:04:00.0: PCI INT A -> GSI 18 (level, low) -> IRQ 18
[ 921.097453] PCI driver Vendor ID = 1204
[ 921.097462] PCI driver Device ID = e250
[ 921.097471] PCI driver Revision = 0

Powerpc output

Quote:

PCI driver: Init function
PCI driver: Probe function
pci_skel 0001:02:00.0: device not available (can't reserve [mem 0x00000000-0x0003ffff])
Unable to Enable PCI device:-22
pci_skel: probe of 0001:02:00.0 failed with error -22

Thanks in advance
Ravi Gupta

archieval · 09-02-2010, 11:05 AM

You are new to linux device driver development but you are already making a PCI driver, one step ahead and you'll be making a usb host/device driver.

Did you build on same linux kernel source for both arch? What is the result of lspci for both arch?

Regards,
archieval

ramukaka · 09-03-2010, 01:44 AM

Quote:

Originally Posted by archieval

You are new to linux device driver development but you are already making a PCI driver, one step ahead and you'll be making a usb host/device driver.

i.e. what you call corporate world ... you do things which you have never done before even if you know nothing about them.

Quote:

Originally Posted by archieval

Did you build on same linux kernel source for both arch? What is the result of lspci for both arch?

No, the i386 machine I am using, is running on linux kernel version 2.6.31 and the one on the powerpc board is linux kernel version 2.6.35. Below is the O/P of lspci command on both the arch. My device is the one named "Non-VGA unclassified device: Lattice Semiconductor Corporation Device e250".

On i386 (linux 2.6.31(open suse))

Quote:

scooby:~ # lspci
00:00.0 Host bridge: Intel Corporation 82G33/G31/P35/P31 Express DRAM Controller (rev 10)
00:01.0 PCI bridge: Intel Corporation 82G33/G31/P35/P31 Express PCI Express Root Port (rev 10)
00:02.0 VGA compatible controller: Intel Corporation 82G33/G31 Express Integrated Graphics Controller (rev 10)
00:1b.0 Audio device: Intel Corporation 82801G (ICH7 Family) High Definition Audio Controller (rev 01)
00:1c.0 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 1 (rev 01)
00:1c.1 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 2 (rev 01)
00:1c.2 PCI bridge: Intel Corporation 82801G (ICH7 Family) PCI Express Port 3 (rev 01)
00:1d.0 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #3 (rev 01)
00:1d.3 USB Controller: Intel Corporation 82801G (ICH7 Family) USB UHCI Controller #4 (rev 01)
00:1d.7 USB Controller: Intel Corporation 82801G (ICH7 Family) USB2 EHCI Controller (rev 01)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev e1)
00:1f.0 ISA bridge: Intel Corporation 82801GB/GR (ICH7 Family) LPC Interface Bridge (rev 01)
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 01)
00:1f.2 IDE interface: Intel Corporation 82801GB/GR/GH (ICH7 Family) SATA IDE Controller (rev 01)
00:1f.3 SMBus: Intel Corporation 82801G (ICH7 Family) SMBus Controller (rev 01)
03:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 01)
04:00.0 Non-VGA unclassified device: Lattice Semiconductor Corporation Device e250
05:06.0 Serial controller: Device 4348:3253 (rev 10)

On PowerPC(linux 2.6.35)

Quote:

# lspci
0000:00:00.0 Power PC: Freescale Semiconductor Inc Unknown device 00c6 (rev 21)
0001:01:00.0 PCI bridge: Freescale Semiconductor Inc Unknown device 00c6 (rev 21)
0001:02:00.0 Non-VGA unclassified device: Lattice Semiconductor Corporation Unknown device e250

One more thing, if I see the contents of /proc/iomem file, I can see the resource range allocated to my device. If resource range is already allocated then why it is saying "device not available (can't reserve [mem 0x00000000-0x0003ffff])" Can you explain the reason for this?

Quote:

cat /proc/iomem -------------------> i386
.
.
.
fe900000-fe9fffff : PCI Bus 0000:04
fe900000-fe93ffff : 0000:04:00.0
fe940000-fe97ffff : 0000:04:00.0
fea00000-feafffff : PCI Bus 0000:03
fea00000-fea1ffff : 0000:03:00.0
fea20000-fea20fff : 0000:03:00.0
fea20000-fea20fff : r8169
.
.
.

Quote:

# cat /proc/iomem ---------> PowerPC
80000000-8fffffff : /pci@e0008500
90000000-9fffffff : /pci@e0008500
a8000000-b7ffffff : /pcie@e0009000
a8000000-a80fffff : PCI Bus 0001:02
c8000000-d7ffffff : /pcie@e000a000
e0004500-e0004507 : serial
e0004600-e0004607 : serial
e0023000-e0023fff : usb

Regards,
Ravi

archieval · 09-03-2010, 03:46 AM

From an old post old post

Quote:

Originally Posted by cladisch

This is printed when same resource that the BIOS says should be reserved has already been reserved by Linux (which already knows that this address should not be used) or by some other BIOS mechanism (there are multiple PnP interfaces).

You snipped the actual address, but this is usually harmless.

here is another relevant post: relevant post

Can you try compiling on same kernel version?

ramukaka · 09-03-2010, 06:25 AM

Quote:

Originally Posted by archieval

Can you try compiling on same kernel version?

yes I tried .... I upgraded the kernel on i386 machine to linux 2.6.35 and it still works giving the same O/P as in case of linux 2.6.31

Quote:

Originally Posted by archieval

This is printed when same resource that the BIOS says should be reserved has already been reserved by Linux (which already knows that this address should not be used) or by some other BIOS mechanism (there are multiple PnP interfaces).

You snipped the actual address, but this is usually harmless.

Can you please elaborate a little bit keeping in mind that it works for i386 arch in my case?

Regards,
Ravi

ramukaka · 09-06-2010, 01:52 AM

Hi Archieval,

I think I got the problem but don't know how to solve it. If everything goes write, then the /proc/iomem contents shouls looks like:

Quote:

80000000-8fffffff : /pci@e0008500
90000000-9fffffff : /pci@e0008500
a8000000-b7ffffff : /pcie@e0009000
a8000000-a803ffff : PCI Bus 0001:02
a8040000-a807ffff : PCI Bus 0001:02
e0004500-e0004507 : serial
e0004600-e0004607 : serial
e0023000-e0023fff : usb

But since the address range "a8000000-a807ffff" is already taken by something else. Actual /proc/iomem contents are:

Quote:

80000000-8fffffff : /pci@e0008500
90000000-9fffffff : /pci@e0008500
a8000000-b7ffffff : /pcie@e0009000
8000000-a80fffff : PCI Bus 0001:02 ---> culprit
e0004500-e0004507 : serial
e0004600-e0004607 : serial
e0023000-e0023fff : usb

Now it looks to me a kernel bug. Do you know where this resource allocation is done, in the kernel code, in case of powerpc arch.

Regards,
Ravi

archieval · 09-06-2010, 03:08 AM

I think it has something to do with the mapping of physical address to kernel virtual address. You can check the probe function of your pci driver and verify the virtual address usually returned by ioremap. Probably the virtual address space is not enough to map additional pci device?