dmaengine: mv_xor: fix big endian operation in register mode
Commit 6f166312c6ea2 ("dmaengine: mv_xor: add support for a38x command
in descriptor mode") introduced the support for a feature that
appeared in Armada 38x: specifying the operation to be performed in a
per-descriptor basis rather than globally per channel.
However, when doing so, it changed the function mv_chan_set_mode() to
use:
if (IS_ENABLED(__BIG_ENDIAN))
instead of:
#if defined(__BIG_ENDIAN)
While IS_ENABLED() is perfectly fine for CONFIG_* symbols, it is not
for other symbols such as __BIG_ENDIAN that is provided directly by
the compiler. Consequently, the commit broke support for big-endian,
as the XOR_DESCRIPTOR_SWAP flag was not set in the XOR channel
configuration register.
The primarily visible effect was some nasty warnings and failures
appearing during the self-test of the XOR unit:
[ 1.197368] mv_xor d0060900.xor: error on chan 0. intr cause 0x00000082
[ 1.197393] mv_xor d0060900.xor: config 0x00008440
[ 1.197410] mv_xor d0060900.xor: activation 0x00000000
[ 1.197427] mv_xor d0060900.xor: intr cause 0x00000082
[ 1.197443] mv_xor d0060900.xor: intr mask 0x000003f7
[ 1.197460] mv_xor d0060900.xor: error cause 0x00000000
[ 1.197477] mv_xor d0060900.xor: error addr 0x00000000
[ 1.197491] ------------[ cut here ]------------
[ 1.197513] WARNING: CPU: 0 PID: 1 at ../drivers/dma/mv_xor.c:664 mv_xor_interrupt_handler+0x14c/0x170()
See also:
http://storage.kernelci.org/next/next-20150617/arm-mvebu_v7_defconfig+CONFIG_CPU_BIG_ENDIAN=y/lab-khilman/boot-armada-xp-openblocks-ax3-4.txt
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Fixes: 6f166312c6ea2 ("dmaengine: mv_xor: add support for a38x command in descriptor mode")
Reviewed-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index fbaf1ea..f1325f6 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -162,10 +162,11 @@
config &= ~0x7;
config |= op_mode;
- if (IS_ENABLED(__BIG_ENDIAN))
- config |= XOR_DESCRIPTOR_SWAP;
- else
- config &= ~XOR_DESCRIPTOR_SWAP;
+#if defined(__BIG_ENDIAN)
+ config |= XOR_DESCRIPTOR_SWAP;
+#else
+ config &= ~XOR_DESCRIPTOR_SWAP;
+#endif
writel_relaxed(config, XOR_CONFIG(chan));
chan->current_type = type;