diff options
| author | Thomas Petazzoni <thomas.petazzoni@free-electrons.com> | 2015-01-28 12:55:45 +0100 |
|---|---|---|
| committer | Andrew Lunn <andrew@lunn.ch> | 2015-01-28 11:23:56 -0600 |
| commit | dcad68876c21bac709b01eda24e39d4410dc36a8 (patch) | |
| tree | bed81a76c1066fd7a9f1f68b30baa7be61d570e5 | |
| parent | 38bdf45f4aa5cb6186d50a29e6cbbd9d486a1519 (diff) | |
ARM: mvebu: don't set the PL310 in I/O coherency mode when I/O coherency is disabled
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>
Cc: <stable@vger.kernel.org> # v3.8+
| -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 caa21e9b8cd9..ccef8806bb58 100644 --- a/arch/arm/mach-mvebu/coherency.c +++ b/arch/arm/mach-mvebu/coherency.c @@ -190,6 +190,13 @@ 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 |