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| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2015-01-28 12:55:45 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-05 22:36:06 -0800 |
| commit | 6ab11bbf0eeed2bf7a2bfb3a7880a0bbed10cbd9 (patch) | |
| tree | fb1b4af5a0f980a9f80ceb58d2acb3a816d95a50 | |
| parent | d5b481842040c799a4e5cec6089d8853d8f540f9 (diff) | |
| download | linux-stable-6ab11bbf0eeed2bf7a2bfb3a7880a0bbed10cbd9.tar.gz linux-stable-6ab11bbf0eeed2bf7a2bfb3a7880a0bbed10cbd9.tar.bz2 linux-stable-6ab11bbf0eeed2bf7a2bfb3a7880a0bbed10cbd9.zip | |
ARM: mvebu: don't set the PL310 in I/O coherency mode when I/O coherency is disabled
commit dcad68876c21bac709b01eda24e39d4410dc36a8 upstream.
Since commit f2c3c67f00 (merge commit that adds commit "ARM: mvebu:
completely disable hardware I/O coherency"), we disable I/O coherency
on Armada EBU platforms.
However, we continue to initialize the coherency fabric, because this
coherency fabric is needed on Armada XP for inter-CPU
coherency. Unfortunately, due to this, we also continued to execute
the coherency fabric initialization code for Armada 375/38x, which
switched the PL310 into I/O coherent mode. This has the effect of
disabling the outer cache sync operation: this is needed when I/O
coherency is enabled to work around a PCIe/L2 deadlock. But obviously,
when I/O coherency is disabled, having the outer cache sync operation
is crucial.
Therefore, this commit fixes the armada_375_380_coherency_init() so
that the PL310 is switched to I/O coherent mode only if I/O coherency
is enabled.
Without this fix, all devices using DMA are broken on Armada 375/38x.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/mach-mvebu/coherency.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c index 1163a3e9accd..2ffccd4eb084 100644 --- a/arch/arm/mach-mvebu/coherency.c +++ b/arch/arm/mach-mvebu/coherency.c @@ -342,6 +342,13 @@ static void __init armada_375_380_coherency_init(struct device_node *np) arch_ioremap_caller = armada_pcie_wa_ioremap_caller; /* + * We should switch the PL310 to I/O coherency mode only if + * I/O coherency is actually enabled. + */ + if (!coherency_available()) + return; + + /* * Add the PL310 property "arm,io-coherent". This makes sure the * outer sync operation is not used, which allows to * workaround the system erratum that causes deadlocks when |