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author | Andres Salomon <dilinger@queued.net> | 2010-12-02 22:31:17 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-12-02 22:51:15 (GMT) |
commit | 853ff88324a248a9f5da6e110850223db353ec07 (patch) | |
tree | 6e48a44c672123d8671af2bffedfefee68133151 /mm | |
parent | 238af8751f64a75f8b638193353b1c31ea32e738 (diff) | |
download | linux-853ff88324a248a9f5da6e110850223db353ec07.tar.xz |
cs5535-gpio: apply CS5536 errata workaround for GPIOs
The AMD Geode CS5536 Companion Device Silicon Revision B1 Specification
Update mentions the follow as issue #36:
"Atomic write transactions to the atomic GPIO High Bank Feature Bit
registers should only affect the bits selected [...]"
"after Suspend, an atomic write transaction [...] will clear all
non-selected bits of the accessed register."
In other words, writing to the high bank for a single GPIO bit will
clear every other GPIO bit (but only sometimes after a suspend).
The workaround described is obvious and simple; do a read-modify-write.
This patch does that, and documents why we're doing it.
Signed-off-by: Andres Salomon <dilinger@queued.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
0 files changed, 0 insertions, 0 deletions