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795eb5c4a7
Current SHPCHP driver doesn't take care of RsvdP/RsvdZ[*] bits
in logical slot registers. This might cause unpredicable results. This
patch fixes this bug.
[*] RsvdP and RsvdZ are defined in SHPC spec as follows:
RsvdP - Reserved and Preserved. Register bits of this type are
reserved for future use as R/W bits. The value read is
undefined. Writes are ignored. Software must follow These rules
when accessing RsvdP bits:
- Software must ignore RsvdP bits when testing values read
from these registers.
- Software must not depend on RsvdP bit's ability to retain
information when written
- Software must always write back the value read in the RsvdP
bits when writing one of these registers.
RsvdZ - Reserved and Zero. Register bits of this type are reserved
for future use as R/WC bits. The value read is undefined. Writes
are ignored. Software must follow these rules when accessing RsvdZ
bits:
- Software must ignore RsvdZ bits when testing values read
from these registers.
- Software must not depends on a RsvdZ bit's ability to retain
information when written.
- Software must always write 0 to RsvdZ bits when writing one
of these register.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Cc: Kristen Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>