4.4-stable review patch. If anyone has any objections, please let me know.
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From: Koen Vandeputte koen.vandeputte@ncentric.com
commit 65dbb423cf28232fed1732b779249d6164c5999b upstream.
Originally, cns3xxx used its own functions for mapping, reading and writing config registers.
Commit 802b7c06adc7 ("ARM: cns3xxx: Convert PCI to use generic config accessors") removed the internal PCI config write function in favor of the generic one:
cns3xxx_pci_write_config() --> pci_generic_config_write()
cns3xxx_pci_write_config() expected aligned addresses, being produced by cns3xxx_pci_map_bus() while the generic one pci_generic_config_write() actually expects the real address as both the function and hardware are capable of byte-aligned writes.
This currently leads to pci_generic_config_write() writing to the wrong registers.
For instance, upon ath9k module loading:
- driver ath9k gets loaded - The driver wants to write value 0xA8 to register PCI_LATENCY_TIMER, located at 0x0D - cns3xxx_pci_map_bus() aligns the address to 0x0C - pci_generic_config_write() effectively writes 0xA8 into register 0x0C (CACHE_LINE_SIZE)
Fix the bug by removing the alignment in the cns3xxx mapping function.
Fixes: 802b7c06adc7 ("ARM: cns3xxx: Convert PCI to use generic config accessors") Signed-off-by: Koen Vandeputte koen.vandeputte@ncentric.com [lorenzo.pieralisi@arm.com: updated commit log] Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Acked-by: Krzysztof Halasa khalasa@piap.pl Acked-by: Tim Harvey tharvey@gateworks.com Acked-by: Arnd Bergmann arnd@arndb.de CC: stable@vger.kernel.org # v4.0+ CC: Bjorn Helgaas bhelgaas@google.com CC: Olof Johansson olof@lixom.net CC: Robin Leblon robin.leblon@ncentric.com CC: Rob Herring robh@kernel.org CC: Russell King linux@armlinux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/arm/mach-cns3xxx/pcie.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm/mach-cns3xxx/pcie.c +++ b/arch/arm/mach-cns3xxx/pcie.c @@ -83,7 +83,7 @@ static void __iomem *cns3xxx_pci_map_bus } else /* remote PCI bus */ base = cnspci->cfg1_regs + ((busno & 0xf) << 20);
- return base + (where & 0xffc) + (devfn << 12); + return base + where + (devfn << 12); }
static int cns3xxx_pci_read_config(struct pci_bus *bus, unsigned int devfn,