[linux-dvb] Re: [PATCH] Re: More than 2Gb problem (dvb related) ?

e9hack e9hack at googlemail.com
Mon Apr 30 08:58:48 CEST 2007


Oliver Endriss wrote:
> After digging through the code, kernel DMA docs and the saa7146
> datasheet, I think that we should remove the scatter-gatter voodoo
> from the budget and av7110 driver. ;-)
> 
> What about the attached patch?
> - easy to understand and maintain
> - saves 1 page of memory (page table of the SAA7146 MMU)
> - saves PCI bandwidth (SAA7146 does not read page table anymore)
> 
> Comments?
> 

pci_alloc_consistent() allocates uncached memory. This makes the demuxer very slow. The 'scatter-gatter voodoo' is a
better solution. If exist a function, which can allocate cached continuous physical memory, you should replace
pci_alloc_consistent() with this function.

- Hartmut



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