When CONFIG_LIBC_BACKTRACE_DEPTH is not set or <= 0, backtrace_get()
is a macro that always sets depth to 0, making the for-loop body
unreachable (Coverity CID 8405332 DEADCODE).
Wrap backtrace_get() call, the loop, and related variable declarations
with #if CONFIG_LIBC_BACKTRACE_DEPTH > 0 to eliminate the dead code
and avoid unused variable warnings.
Signed-off-by: guanyi3 <guanyi3@xiaomi.com>
The cached devfreq->cur may become stale when the hardware frequency is
changed externally (e.g. by another core or governor). This causes
driver_target to incorrectly skip frequency transitions when the target
matches the cached value but differs from the actual hardware frequency.
Use driver->get_frequency() to read the real hardware frequency for the
unchanged check, and sync devfreq->cur on match to keep the cache correct.
Signed-off-by: guanyi3 <guanyi3@xiaomi.com>
Add the ability to set frequency constraints via procfs write.
Supported formats:
echo <min>,<max> > /proc/devfreq/<name> - set frequency range
echo 0,0 > /proc/devfreq/<name> - remove constraint
The QoS request is bound to the devfreq device lifetime so that
shell commands like echo (which open, write, close immediately)
work correctly. Leading whitespace in the write buffer is skipped
to handle extra writes from nsh echo (e.g. trailing newline).
Also add write permissions in devfreq_stat() and a procfs_qos
field in devfreq_s guarded by CONFIG_DEVFREQ_PROCFS.
Signed-off-by: guanyi3 <guanyi3@xiaomi.com>
(cherry picked from commit 70ae195c84f35a4d0b85fcc14187989b60fc0280)
