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| author | Alexander Sverdlin <alexander.sverdlin@nokia.com> | 2015-03-18 14:05:21 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2015-08-07 00:32:19 +0100 |
| commit | 53493d44a771a3155ee12b6ac668fb2543d21a7a (patch) | |
| tree | f76a8669636a63033546c652e7f1bdf8e8187557 /arch | |
| parent | 6bde6a3df0b4c8680d51c987d446b0ff2d6df0a6 (diff) | |
| download | kernel_samsung_smdk4412-53493d44a771a3155ee12b6ac668fb2543d21a7a.zip kernel_samsung_smdk4412-53493d44a771a3155ee12b6ac668fb2543d21a7a.tar.gz kernel_samsung_smdk4412-53493d44a771a3155ee12b6ac668fb2543d21a7a.tar.bz2 | |
MIPS: Octeon: Remove udelay() causing huge IRQ latency
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@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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch')
| -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 | 3 |
3 files changed, 0 insertions, 12 deletions
diff --git a/arch/mips/include/asm/octeon/pci-octeon.h b/arch/mips/include/asm/octeon/pci-octeon.h index fba2ba2..ac83283 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 ed1c542..66d3c38 100644 --- a/arch/mips/pci/pci-octeon.c +++ b/arch/mips/pci/pci-octeon.c @@ -279,9 +279,6 @@ 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)); @@ -316,9 +313,6 @@ 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 0583c46..37a8790 100644 --- a/arch/mips/pci/pcie-octeon.c +++ b/arch/mips/pci/pcie-octeon.c @@ -1219,9 +1219,6 @@ 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; } |