ixp4xx: add Mikael Petterssons patch works for 2.6.33 & 2.6.35

[openwrt/svn-archive/archive.git] / target / linux / ixp4xx / patches-2.6.35 / 050-disable_dmabounce.patch

diff --git a/target/linux/ixp4xx/patches-2.6.35/050-disable_dmabounce.patch b/target/linux/ixp4xx/patches-2.6.35/050-disable_dmabounce.patch
index 83e2a4964f1770d553fc4f5553fc85f9fd412f1a..f5d0a58c6c2d652a278498cb5273e07ffb1e44aa 100644 (file)
--- a/target/linux/ixp4xx/patches-2.6.35/050-disable_dmabounce.patch
+++ b/target/linux/ixp4xx/patches-2.6.35/050-disable_dmabounce.patch
@@ -1,8 +1,8 @@
 --- a/arch/arm/Kconfig
 +++ b/arch/arm/Kconfig
-@@ -417,7 +417,6 @@ config ARCH_IXP4XX
+@@ -435,7 +435,6 @@ config ARCH_IXP4XX
+       select CPU_XSCALE
        select GENERIC_GPIO
-       select GENERIC_TIME
        select GENERIC_CLOCKEVENTS
 -      select DMABOUNCE if PCI
        help
@@ -10,26 +10,24 @@
  
 --- a/arch/arm/mach-ixp4xx/Kconfig
 +++ b/arch/arm/mach-ixp4xx/Kconfig
-@@ -199,6 +199,45 @@ config IXP4XX_INDIRECT_PCI
+@@ -199,6 +199,43 @@ config IXP4XX_INDIRECT_PCI
          need to use the indirect method instead. If you don't know
          what you need, leave this option unselected.
  
 +config IXP4XX_LEGACY_DMABOUNCE
-+      bool "legacy PCI DMA bounce support"
++      bool "Legacy PCI DMA bounce support"
 +      depends on PCI
 +      default n
 +      select DMABOUNCE
 +      help
 +        The IXP4xx is limited to a 64MB window for PCI DMA, which
-+        requires that PCI accesses above 64MB are bounced via buffers
-+        below 64MB. Furthermore the IXP4xx has an erratum where PCI
-+        read prefetches just below the 64MB limit can trigger lockups.
++        requires that PCI accesses >= 64MB are bounced via buffers
++        below 64MB.
 +
-+        The kernel has traditionally handled these two issue by using
-+        ARM specific DMA bounce support code for all accesses >= 64MB.
++        The kernel has traditionally handled this issue by using ARM
++        specific DMA bounce support code for all accesses >= 64MB.
 +        That code causes problems of its own, so it is desirable to
-+        disable it. As the kernel now has a workaround for the PCI read
-+        prefetch erratum, it no longer requires the ARM bounce code.
++        disable it.
 +
 +        Enabling this option makes IXP4xx continue to use the problematic
 +        ARM DMA bounce code. Disabling this option makes IXP4xx use the
@@ -58,7 +56,7 @@
        help
 --- a/arch/arm/mach-ixp4xx/common-pci.c
 +++ b/arch/arm/mach-ixp4xx/common-pci.c
-@@ -321,27 +321,38 @@ static int abort_handler(unsigned long a
+@@ -321,27 +321,33 @@ static int abort_handler(unsigned long a
   */
  static int ixp4xx_pci_platform_notify(struct device *dev)
  {
@@ -88,12 +86,8 @@
 +#ifdef CONFIG_DMABOUNCE
  int dma_needs_bounce(struct device *dev, dma_addr_t dma_addr, size_t size)
  {
-+      /* Note that this returns true for the last page below 64M due to
-+       * IXP4xx erratum 15 (SCR 1289), which states that PCI prefetches
-+       * can cross the boundary between valid memory and a reserved region
-+       * causing AHB bus errors and a lock-up.
-+       */
-       return (dev->bus == &pci_bus_type ) && ((dma_addr + size) >= SZ_64M);
+-      return (dev->bus == &pci_bus_type ) && ((dma_addr + size) >= SZ_64M);
++      return (dev->bus == &pci_bus_type ) && ((dma_addr + size) > SZ_64M);
  }
 +#endif
  
@@ -101,7 +95,7 @@
  /*
   * Only first 64MB of memory can be accessed via PCI.
   * We use GFP_DMA to allocate safe buffers to do map/unmap.
-@@ -364,6 +375,7 @@ void __init ixp4xx_adjust_zones(int node
+@@ -364,6 +370,7 @@ void __init ixp4xx_adjust_zones(int node
        zhole_size[1] = zhole_size[0];
        zhole_size[0] = 0;
  }