Commit Graph

2 Commits

Author SHA1 Message Date
Arnd Bergmann
3482704132 ANDROID: memory_state_time: fix undefined behavior with missing DT properties
kernelci reports warnings about unintialized variable usage:

drivers/misc/memory_state_time.c:351:12: warning: 'lenf' is used uninitialized in this function [-Wuninitialized]
drivers/misc/memory_state_time.c:321:14: warning: 'lenb' is used uninitialized in this function [-Wuninitialized]

In both cases we try to continue without a DT property but use the
length that has not been assigned at this point. This rearranges the
code in the two functions to bail out earlier in case of an error.

The patch is needed for both android-common-4.9, 4.4 and 3.18.

Link: https://kernelci.org/build/id/591177f459b5147648b12d54/logs/
Fixes: ad3c02f8b3 ("ANDROID: Implement memory_state_time, used by qcom,cpubw")
Cc: James Carr <carrja@google.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-05-12 14:41:44 +02:00
James Carr
ad3c02f8b3 ANDROID: Implement memory_state_time, used by qcom,cpubw
New driver memory_state_time tracks time spent in different DDR
frequency and bandwidth states.

Memory drivers such as qcom,cpubw can post updated state to the driver
after registering a callback. Processed by a workqueue

Bandwidth buckets are read in from device tree in the relevant qualcomm
section, can be defined in any quantity and spacing.

The data is exposed at /sys/kernel/memory_state_time, able to be read by
the Android framework.

Functionality is behind a config option CONFIG_MEMORY_STATE_TIME

Change-Id: I4fee165571cb975fb9eacbc9aada5e6d7dd748f0
Signed-off-by: James Carr <carrja@google.com>
2017-01-31 10:45:55 -08:00