diff options
| author | Alexander Sverdlin <alexander.sverdlin@nokia.com> | 2015-03-18 14:05:21 +0100 |
|---|---|---|
| committer | Ralf Baechle <ralf@linux-mips.org> | 2015-04-10 15:41:42 +0200 |
| commit | 73bf3c2a500b2db8ac966469591196bf55afb409 (patch) | |
| tree | 1ca3d97a0cf83fce6287ce201af6acdb2ee60e3f | |
| parent | MIPS: Fix race condition in lazy cache flushing. (diff) | |
| download | linux-73bf3c2a500b2db8ac966469591196bf55afb409.tar.xz linux-73bf3c2a500b2db8ac966469591196bf55afb409.zip | |
MIPS: Octeon: Remove udelay() causing huge IRQ latency
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@nokia.com>
Cc: linux-mips@linux-mips.org
Cc: David Daney <ddaney@cavium.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Masanari Iida <standby24x7@gmail.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Mathias <mathias.rulf@nokia.com>
Patchwork: https://patchwork.linux-mips.org/patch/9576/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
| -rw-r--r-- | arch/mips/include/asm/octeon/pci-octeon.h | 3 | ||||
| -rw-r--r-- | arch/mips/pci/pci-octeon.c | 6 | ||||
| -rw-r--r-- | arch/mips/pci/pcie-octeon.c | 8 |
3 files changed, 0 insertions, 17 deletions
diff --git a/arch/mips/include/asm/octeon/pci-octeon.h b/arch/mips/include/asm/octeon/pci-octeon.h index 64ba56a02843..1884609741a8 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 - /* * The physical memory base mapped by BAR1. 256MB at the end of the * first 4GB. diff --git a/arch/mips/pci/pci-octeon.c b/arch/mips/pci/pci-octeon.c index a04af55d89f1..01c604a5ac36 100644 --- a/arch/mips/pci/pci-octeon.c +++ b/arch/mips/pci/pci-octeon.c @@ -271,9 +271,6 @@ 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)); @@ -308,9 +305,6 @@ 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 1bb0b2bf8d6e..99f3db4f0a9b 100644 --- a/arch/mips/pci/pcie-octeon.c +++ b/arch/mips/pci/pcie-octeon.c @@ -1762,14 +1762,6 @@ static int octeon_pcie_write_config(unsigned int pcie_port, struct pci_bus *bus, default: return PCIBIOS_FUNC_NOT_SUPPORTED; } -#if PCI_CONFIG_SPACE_DELAY - /* - * Delay on writes so that devices have time to come up. Some - * bridges need this to allow time for the secondary busses to - * work - */ - udelay(PCI_CONFIG_SPACE_DELAY); -#endif return PCIBIOS_SUCCESSFUL; } |