Suresh Siddha wrote: > If we are going to make ioremap() and set_memory_wc() add mtrr's in > non-pat case, then we need to delete the added mtrr(s) in the > corresponding iounmap() and set_memory_wb() aswell. > > hmm, this is becoming too complex. The way i915 and other graphics > drivers are using set_memory_wc(), it is def a bad idea to start adding > mtrr's behind the back for non-pat case.
Yes, maybe it's better to drop it for ioremap() and set_memory_wc(). But I'd like to keep it for mmapping the PCI region. It should help all the people with PAT-incapable CPUs and graphics chips without DRM support (for them there simply is no driver that should set up the MTRR entries...). > Can't we just force PAT option always and we probably don't care about > ioremap_wc() on processors were PAT doesn't get enabled because of known > errata. I don't think this is a good idea, Robert Hancock wrote there may be millions of such Laptops (Core Solo/Duo erratum AE7, Pentium M erratum Y31) : http://marc.info/?l=linux-kernel&m=125537136105246&w=2 > or Perhaps just try to add mtrr only for the pci mmap case like the 4th > patch in this series.. I'd prefer this! ;-) Kind regards, Thomas ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
