PCI changes 2.6.26 => 2.6.28
Gary Thomas
gary at mlbassoc.com
Wed Apr 22 06:32:39 EST 2009
Gary Thomas wrote:
> Gary Thomas wrote:
>> I had a stable port of 2.6.26 for my 834x hardware, with a
>> frame buffer on a PCI device. After I upgraded to 2.6.28,
>> this isn't working any more. The frame buffer code is happily
>> writing to a mapped [memory] space on the PCI card, but nothing
>> is happening.
>>
>> Did something [subtle] change in how the PCI is handled in
>> this timeframe? Perhaps with how PCI devices are mapped or
>> enabled? I've looked at the changes between the two versions,
>> but nothing leaps out at me.
>>
>> n.b. I have other devices on the PCI bus, such as a SATA
>> controller, which work the same in both versions.
>>
>> Thanks for any ideas
>>
>
> The difference seems to be in how the PCI bus gets mapped.
>
> In the working, 2.6.26 based kernel, 'lspci -v' shows this:
>
> 00:00.0 Bridge: Unknown device 1957:0084 (rev 11)
> Flags: bus master, 66MHz, fast devsel, latency 0
> Memory at cc000000 (32-bit, non-prefetchable) [size=1M]
> Memory at c0000000 (64-bit, prefetchable) [size=128M]
> Memory at cc143100 (64-bit, non-prefetchable) [size=1]
> Capabilities: [48] #06 [0000]
>
> 00:0a.0 Network controller: Unknown device 001c:0001 (rev 02)
> Subsystem: Unknown device 001c:0004
> Flags: medium devsel, IRQ 22
> Memory at cc120000 (32-bit, non-prefetchable) [size=64K]
> Memory at cc130000 (32-bit, non-prefetchable) [size=64K]
>
> 00:0b.0 Mass storage controller: Promise Technology, Inc. PDC40775 (SATA 300 TX2plus) (rev 02)
> Subsystem: Promise Technology, Inc. Unknown device 3573
> Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 23
> I/O ports at 1000 [size=128]
> I/O ports at 1100 [size=256]
> Memory at cc140000 (32-bit, non-prefetchable) [size=4K]
> Memory at cc100000 (32-bit, non-prefetchable) [size=128K]
> Capabilities: [60] Power Management version 2
>
> 00:0c.0 Display controller: Fujitsu Limited. Unknown device 2019 (rev 01)
> Flags: bus master, medium devsel, latency 0, IRQ 24
> Memory at c8000000 (32-bit, non-prefetchable) [size=64M]
>
> 00:0d.0 USB Controller: Philips Semiconductors USB 1.1 Host Controller (rev 11) (prog-if 10 [OHCI])
> Subsystem: Philips Semiconductors USB 1.1 Host Controller
> Flags: bus master, medium devsel, latency 0, IRQ 25
> Memory at cc141000 (32-bit, non-prefetchable) [size=4K]
> Capabilities: [dc] Power Management version 2
>
> 00:0d.1 USB Controller: Philips Semiconductors USB 1.1 Host Controller (rev 11) (prog-if 10 [OHCI])
> Subsystem: Philips Semiconductors USB 1.1 Host Controller
> Flags: bus master, medium devsel, latency 0, IRQ 25
> Memory at cc142000 (32-bit, non-prefetchable) [size=4K]
> Capabilities: [dc] Power Management version 2
>
> 00:0d.2 USB Controller: Philips Semiconductors USB 2.0 Host Controller (rev 11) (prog-if 20 [EHCI])
> Subsystem: Philips Semiconductors USB 2.0 Host Controller
> Flags: bus master, medium devsel, latency 0, IRQ 25
> Memory at cc143000 (32-bit, non-prefetchable) [size=256]
> Capabilities: [dc] Power Management version 2
>
> This is what 2.6.28 shows:
>
> 00:00.0 Bridge: Unknown device 1957:0084 (rev 11)
> Flags: bus master, 66MHz, fast devsel, latency 0
> Memory at <unassigned> (64-bit, prefetchable)
> Memory at <unassigned> (64-bit, non-prefetchable)
> Capabilities: [48] #06 [0000]
>
> 00:0a.0 Network controller: Unknown device 001c:0001 (rev 02)
> Subsystem: Unknown device 001c:0004
> Flags: medium devsel, IRQ 16
> Memory at c4020000 (32-bit, non-prefetchable) [size=64K]
> Memory at c4030000 (32-bit, non-prefetchable) [size=64K]
>
> 00:0b.0 Mass storage controller: Promise Technology, Inc. PDC40775 (SATA 300 TX2plus) (rev 02)
> Subsystem: Promise Technology, Inc. Unknown device 3573
> Flags: bus master, 66MHz, medium devsel, latency 0, IRQ 21
> I/O ports at 1000 [size=128]
> I/O ports at 1100 [size=256]
> Memory at c4040000 (32-bit, non-prefetchable) [size=4K]
> Memory at c4000000 (32-bit, non-prefetchable) [size=128K]
> Capabilities: [60] Power Management version 2
>
> 00:0c.0 Display controller: Fujitsu Limited. Unknown device 2019 (rev 01)
> Flags: bus master, medium devsel, latency 0, IRQ 22
> [virtual] Memory at c0000000 (32-bit, non-prefetchable) [size=64M]
>
> 00:0d.0 USB Controller: Philips Semiconductors USB 1.1 Host Controller (rev 11) (prog-if 10 [OHCI])
> Subsystem: Philips Semiconductors USB 1.1 Host Controller
> Flags: bus master, medium devsel, latency 0, IRQ 23
> Memory at c4041000 (32-bit, non-prefetchable) [size=4K]
> Capabilities: [dc] Power Management version 2
>
> 00:0d.1 USB Controller: Philips Semiconductors USB 1.1 Host Controller (rev 11) (prog-if 10 [OHCI])
> Subsystem: Philips Semiconductors USB 1.1 Host Controller
> Flags: bus master, medium devsel, latency 0, IRQ 23
> Memory at c4042000 (32-bit, non-prefetchable) [size=4K]
> Capabilities: [dc] Power Management version 2
>
> 00:0d.2 USB Controller: Philips Semiconductors USB 2.0 Host Controller (rev 11) (prog-if 20 [EHCI])
> Subsystem: Philips Semiconductors USB 2.0 Host Controller
> Flags: bus master, medium devsel, latency 0, IRQ 23
> Memory at c4043000 (32-bit, non-prefetchable) [size=256]
> Capabilities: [dc] Power Management version 2
>
> The [two] big differences I see are that the video card (00:0d.0)
> is being assigned 0xC0000000, which lspci marks as "virtual".
> I think I've had trouble in the past with memory regions which
> started at 0 relative to the PCI space. Also "virtual" concerns me.
>
> Does this spark any ideas from anyone?
>
n.b. "virtual" means that Linux reports that the device has
been mapped to 0xC0000000, but the device address register
is still unset :-( How can this happen?
--
------------------------------------------------------------
Gary Thomas | Consulting for the
MLB Associates | Embedded world
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