• Jorge Ramirez-Ortiz's avatar
    clk: qcom: hfpll: CLK_IGNORE_UNUSED · e97d5075
    Jorge Ramirez-Ortiz authored
    When COMMON_CLK_DISABLED_UNUSED is set, in an effort to save power and
    to keep the software model of the clock in line with reality, the
    framework transverses the clock tree and disables those clocks that
    were enabled by the firmware but have not been enabled by any device
    driver.
    
    If CPUFREQ is enabled, early during the system boot, it might attempt
    to change the CPU frequency ("set_rate"). If the HFPLL is selected as
    a provider, it will then change the rate for this clock.
    
    As boot continues, clk_disable_unused_subtree will run. Since it wont
    find a valid counter (enable_count) for a clock that is actually
    enabled it will attempt to disable it which will cause the CPU to
    stop. Notice that in this driver, calls to check whether the clock is
    enabled are routed via the is_enabled callback which queries the
    hardware.
    
    The following commit, rather than marking the clock critical and
    forcing the clock to be always enabled, addresses the above scenario
    making sure the clock is not disabled but it continues to rely on the
    firmware to enable the clock.
    Co-developed-by: default avatarNiklas Cassel <[email protected]>
    Signed-off-by: default avatarNiklas Cassel <[email protected]>
    Signed-off-by: default avatarJorge Ramirez-Ortiz <[email protected]>
    e97d5075
hfpll.c 2.64 KB