Re: [PATCH] MIPS: pci-legacy: Override pci_address_to_pio

[Jiaxun Yang]

在2025年1月14日一月 下午6:46，Greg KH写道：
> On Tue, Jan 14, 2025 at 06:11:58PM +0000, Jiaxun Yang wrote:
>> pci-legacy systems are not using logic_pio to managed PIO
>> allocations, thus the generic pci_address_to_pio won't work
>> when PCI_IOBASE is defined.
>> 
>> Override the function to use architecture implementation to
>> fix the problem.
>> 
>> Cc: stable@xxxxxxxxxxxxxxx
>> Fixes: 4bfb53e7d317 ("mips: add <asm-generic/io.h> including")
>> Reported-by: Mateusz Jończyk <mat.jonczyk@xxxxx>
>> Closes: https://lore.kernel.org/r/99f75c66-4c2d-45dc-a808-b5ba440c7551@xxxxxxxxxxxxxxxx/
>> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
>> ---
>> This is a quick fix for fixes tree and stable backporting.
>> In long term, we should get logic_pio accept fixed mapping,
>> and make PCI core code aware of platforms not using vmap
>> for PCI_IOBASE.
>
> Why not do the real work now.  Don't worry about stable kernels, fix it
> properly.

:-( Sadly the long-term solution is going to be a huge effort across
architectures, and I'm not even sure if people will agree with my approach.
So I'd prefer get this fix applied first and kick up discussions on a
long-term solution. 

Will post RFC shortly. 

Thanks
>
> thanks,
>
> greg k-h

-- 
- Jiaxun