diff options
Diffstat (limited to 'target/linux/ixp4xx/patches-2.6.33/050-disable_dmabounce.patch')
| -rw-r--r-- | target/linux/ixp4xx/patches-2.6.33/050-disable_dmabounce.patch | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/target/linux/ixp4xx/patches-2.6.33/050-disable_dmabounce.patch b/target/linux/ixp4xx/patches-2.6.33/050-disable_dmabounce.patch new file mode 100644 index 0000000000..34de296b3d --- /dev/null +++ b/target/linux/ixp4xx/patches-2.6.33/050-disable_dmabounce.patch @@ -0,0 +1,164 @@ +--- a/arch/arm/Kconfig ++++ b/arch/arm/Kconfig +@@ -418,7 +418,6 @@ config ARCH_IXP4XX + select GENERIC_GPIO + select GENERIC_TIME + select GENERIC_CLOCKEVENTS +- select DMABOUNCE if PCI + help + Support for Intel's IXP4XX (XScale) family of processors. + +--- a/arch/arm/mach-ixp4xx/Kconfig ++++ b/arch/arm/mach-ixp4xx/Kconfig +@@ -199,6 +199,45 @@ 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" ++ 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. ++ ++ The kernel has traditionally handled these two 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. ++ ++ Enabling this option makes IXP4xx continue to use the problematic ++ ARM DMA bounce code. Disabling this option makes IXP4xx use the ++ kernel's generic bounce code. ++ ++ Say 'N'. ++ ++config IXP4XX_ZONE_DMA ++ bool "Support > 64MB RAM" ++ depends on !IXP4XX_LEGACY_DMABOUNCE ++ default y ++ select ZONE_DMA ++ 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. ++ ++ Disabling this option allows you to omit the support code for ++ DMA-able memory allocations and DMA bouncing, but the kernel ++ will then not work properly if more than 64MB of RAM is present. ++ ++ Say 'Y' unless your platform is limited to <= 64MB of RAM. ++ + config IXP4XX_QMGR + tristate "IXP4xx Queue Manager support" + 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 + */ + static int ixp4xx_pci_platform_notify(struct device *dev) + { +- if(dev->bus == &pci_bus_type) { +- *dev->dma_mask = SZ_64M - 1; ++ if (dev->bus == &pci_bus_type) { ++ *dev->dma_mask = SZ_64M - 1; + dev->coherent_dma_mask = SZ_64M - 1; ++#ifdef CONFIG_DMABOUNCE + dmabounce_register_dev(dev, 2048, 4096); ++#endif + } + return 0; + } + + static int ixp4xx_pci_platform_notify_remove(struct device *dev) + { +- if(dev->bus == &pci_bus_type) { ++#ifdef CONFIG_DMABOUNCE ++ if (dev->bus == &pci_bus_type) + dmabounce_unregister_dev(dev); +- } ++#endif + return 0; + } + ++#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); + } ++#endif + ++#ifdef CONFIG_ZONE_DMA + /* + * 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 + zhole_size[1] = zhole_size[0]; + zhole_size[0] = 0; + } ++#endif + + void __init ixp4xx_pci_preinit(void) + { +@@ -517,19 +529,35 @@ struct pci_bus * __devinit ixp4xx_scan_b + int + pci_set_dma_mask(struct pci_dev *dev, u64 mask) + { +- if (mask >= SZ_64M - 1 ) ++#ifdef CONFIG_DMABOUNCE ++ if (mask >= SZ_64M - 1) + return 0; + + return -EIO; ++#else ++ /* Only honour masks < SZ_64M. Silently ignore masks >= SZ_64M ++ as generic drivers do not know about IXP4xx PCI DMA quirks. */ ++ if (mask < SZ_64M) ++ dev->dma_mask = mask; ++ return 0; ++#endif + } + + int + pci_set_consistent_dma_mask(struct pci_dev *dev, u64 mask) + { +- if (mask >= SZ_64M - 1 ) ++#ifdef CONFIG_DMABOUNCE ++ if (mask >= SZ_64M - 1) + return 0; + + return -EIO; ++#else ++ /* Only honour masks < SZ_64M. Silently ignore masks >= SZ_64M ++ as generic drivers do not know about IXP4xx PCI DMA quirks. */ ++ if (mask < SZ_64M) ++ dev->dev.coherent_dma_mask = mask; ++ return 0; ++#endif + } + + EXPORT_SYMBOL(ixp4xx_pci_read); +--- a/arch/arm/mach-ixp4xx/include/mach/memory.h ++++ b/arch/arm/mach-ixp4xx/include/mach/memory.h +@@ -16,10 +16,12 @@ + + #if !defined(__ASSEMBLY__) && defined(CONFIG_PCI) + ++#ifdef CONFIG_ZONE_DMA + void ixp4xx_adjust_zones(int node, unsigned long *size, unsigned long *holes); + + #define arch_adjust_zones(node, size, holes) \ + ixp4xx_adjust_zones(node, size, holes) ++#endif + + #define ISA_DMA_THRESHOLD (SZ_64M - 1) + #define MAX_DMA_ADDRESS (PAGE_OFFSET + SZ_64M) |