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  1. Oct 12, 2007
    • David Brownell's avatar
      dma_free_coherent() needs irqs enabled (sigh) · aa24886e
      David Brownell authored
      
      On at least ARM (and I'm told MIPS too) dma_free_coherent() has a newish
      call context requirement: unlike its dma_alloc_coherent() sibling, it may
      not be called with IRQs disabled.  (This was new behavior on ARM as of late
      2005, caused by ARM SMP updates.) This little surprise can be annoyingly
      driver-visible.
      
      Since it looks like that restriction won't be removed, this patch changes
      the definition of the API to include that requirement.  Also, to help catch
      nonportable drivers, it updates the x86 and swiotlb versions to include the
      relevant warnings.  (I already observed that it trips on the
      bus_reset_tasklet of the new firewire_ohci driver.)
      
      Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
      Cc: David Miller <davem@davemloft.net>
      Acked-by: default avatarRussell King <rmk@arm.linux.org.uk>
      Cc: Andi Kleen <ak@suse.de>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      aa24886e
  2. Jul 31, 2007
  3. Dec 07, 2006
  4. Nov 30, 2006
  5. Apr 14, 2006
    • David Brownell's avatar
      [PATCH] dma doc updates · 21440d31
      David Brownell authored
      
      This updates the DMA API documentation to address a few issues:
      
       - The dma_map_sg() call results are used like pci_map_sg() results:
         using sg_dma_address() and sg_dma_len().  That's not wholly obvious
         to folk reading _only_ the "new" DMA-API.txt writeup.
      
       - Buffers allocated by dma_alloc_coherent() may not be completely
         free of coherency concerns ... some CPUs also have write buffers
         that may need to be flushed.
      
       - Cacheline coherence issues are now mentioned as being among issues
         which affect dma buffers, and complicate/prevent using of static and
         (especially) stack based buffers with the DMA calls.
      
      I don't think many drivers currently need to worry about flushing write
      buffers, but I did hit it with one SOC using external SDRAM for DMA
      descriptors:  without explicit writebuffer flushing, the on-chip DMA
      controller accessed descriptors before the CPU completed the writes.
      
      Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
      21440d31
  6. Sep 10, 2005
  7. Apr 16, 2005
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4
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