2.6.32-longterm review patch. If anyone has any objections, please let me know. ------------------ From: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx> commit 73bf3c2a500b2db8ac966469591196bf55afb409 upstream. udelay() in PCI/PCIe read/write callbacks cause 30ms IRQ latency on Octeon platforms because these operations are called from PCI_OP_READ() and PCI_OP_WRITE() under raw_spin_lock_irqsave(). Signed-off-by: Alexander Sverdlin <alexander.sverdlin@xxxxxxxxx> Cc: linux-mips@xxxxxxxxxxxxxx Cc: David Daney <ddaney@xxxxxxxxxx> Cc: Rob Herring <robh@xxxxxxxxxx> Cc: Jiri Kosina <jkosina@xxxxxxx> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Cc: Masanari Iida <standby24x7@xxxxxxxxx> Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx> Cc: Mathias <mathias.rulf@xxxxxxxxx> Patchwork: https://patchwork.linux-mips.org/patch/9576/ Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx> [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx> (cherry picked from commit 53493d44a771a3155ee12b6ac668fb2543d21a7a) Signed-off-by: Willy Tarreau <w@xxxxxx> --- arch/mips/include/asm/octeon/pci-octeon.h | 3 --- arch/mips/pci/pci-octeon.c | 6 ------ arch/mips/pci/pcie-octeon.c | 3 --- 3 files changed, 12 deletions(-) diff --git a/arch/mips/include/asm/octeon/pci-octeon.h b/arch/mips/include/asm/octeon/pci-octeon.h index 6ac5d3e..5eda9f0 100644 --- a/arch/mips/include/asm/octeon/pci-octeon.h +++ b/arch/mips/include/asm/octeon/pci-octeon.h @@ -11,9 +11,6 @@ #include <linux/pci.h> -/* Some PCI cards require delays when accessing config space. */ -#define PCI_CONFIG_SPACE_DELAY 10000 - /* * pcibios_map_irq() is defined inside pci-octeon.c. All it does is * call the Octeon specific version pointed to by this variable. This diff --git a/arch/mips/pci/pci-octeon.c b/arch/mips/pci/pci-octeon.c index 9cb0c80..dae7ff7 100644 --- a/arch/mips/pci/pci-octeon.c +++ b/arch/mips/pci/pci-octeon.c @@ -274,9 +274,6 @@ static int octeon_read_config(struct pci_bus *bus, unsigned int devfn, pci_addr.s.func = devfn & 0x7; pci_addr.s.reg = reg; -#if PCI_CONFIG_SPACE_DELAY - udelay(PCI_CONFIG_SPACE_DELAY); -#endif switch (size) { case 4: *val = le32_to_cpu(cvmx_read64_uint32(pci_addr.u64)); @@ -311,9 +308,6 @@ static int octeon_write_config(struct pci_bus *bus, unsigned int devfn, pci_addr.s.func = devfn & 0x7; pci_addr.s.reg = reg; -#if PCI_CONFIG_SPACE_DELAY - udelay(PCI_CONFIG_SPACE_DELAY); -#endif switch (size) { case 4: cvmx_write64_uint32(pci_addr.u64, cpu_to_le32(val)); diff --git a/arch/mips/pci/pcie-octeon.c b/arch/mips/pci/pcie-octeon.c index 6aa5c54..97813f3 100644 --- a/arch/mips/pci/pcie-octeon.c +++ b/arch/mips/pci/pcie-octeon.c @@ -1192,9 +1192,6 @@ static inline int octeon_pcie_write_config(int pcie_port, struct pci_bus *bus, devfn & 0x7, reg, val); return PCIBIOS_SUCCESSFUL; } -#if PCI_CONFIG_SPACE_DELAY - udelay(PCI_CONFIG_SPACE_DELAY); -#endif return PCIBIOS_FUNC_NOT_SUPPORTED; } -- 1.7.12.2.21.g234cd45.dirty
