[PATCH] powerpc/5200: Bugfix for PCI mapping of memory and IMMR

Andre Schwarz andre.schwarz at matrix-vision.de
Fri Jan 30 19:33:03 EST 2009

Matt Sealey wrote:
> On Mon, Jan 26, 2009 at 10:34 PM, Grant Likely
> <grant.likely at secretlab.ca> wrote:
>> From: Grant Likely <grant.likely at secretlab.ca>
>> This patch ensures that memory gets properly mapped into the PCI
>> address space.  Without this patch, the memory window BAR is left
>> at whatever value happened to be loaded into the BAR when Linux
>> was booted.  Without this patch, memory could end up getting mapped
>> at any of the 1G address boundaries instead of at '0' where Linux
>> expects it.
>> Similarly, this patch also ensures that the internally memory mapped
>> registers (IMMR) are mapped to the correct PCI address range.
>> Without this patch, PCI appears to work correctly until a PCI
>> device is inserted which DMAs into memory.
>> Signed-off-by: Grant Likely <grant.likely at secretlab.ca>
>> ---
>> This is a bugfix that I intend to merge into 2.6.29 and once it is
>> mainlined get it added to the stable queue.  If you have a 5200 system,
>> please test and make sure it works for you.
>> Thanks
>> g.
>>  arch/powerpc/platforms/52xx/mpc52xx_pci.c |   24 ++++++++++--------------
>>  1 files changed, 10 insertions(+), 14 deletions(-)
> This doesn't affect Efika, right?
> What's the expected impact and how come nobody tried a DMA-capable PCI
> card in an MPC5200B board before? :)
We're running a MPC5200B based board with an external FPGA pumping as 
much data into the CPU's memory as possible using scatter-gather DMA. No 
problems so far ... besides the lousy PCI target performance of the 
5200, of course. Of course we've been always running latest u-boot.


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