Lada Trimasova f640dae894 ARC: [BE] readl()/writel() to work in Big Endian CPU configuration ...

commit f778cc6571 upstream.

read{l,w}() write{l,w}() primitives should use le{16,32}_to_cpu() and
cpu_to_le{16,32}() respectively to ensure device registers are read
correctly in Big Endian CPU configuration.

Per Arnd Bergmann
| Most drivers using readl() or readl_relaxed() expect those to perform byte
| swaps on big-endian architectures, as the registers tend to be fixed endian

This was needed for getting UART to work correctly on a Big Endian ARC.

The ARC accessors originally were fine, and the bug got introduced
inadventently by commit b8a0330239 ("ARCv2: barriers")

Fixes: b8a0330239 ("ARCv2: barriers")
Link: http://lkml.kernel.org/r/201603100845.30602.arnd@arndb.de
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lada Trimasova <ltrimas@synopsys.com>
[vgupta: beefed up changelog, added Fixes/stable tags]
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2016-04-12 09:08:56 -07:00

3.8 KiB

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