Hello, On Thu, Sep 01, 2016 at 05:09:36PM +0800, qiaozhou wrote: > In our system, we do cpu clock init in of_clk_init path, and use pm qos to > maintain cpu/cci clock. Firstly we init a CCI_CLK_QOS and set a default > value, then update CCI_CLK_QOS to limit CCI min frequency according to > current cpu frequency. Before calling pm_qos_update_request, irq is > disabled, but after the calling, irq is enabled in cancel_delayed_work_sync, > which causes some inconvenience before Before this patch is applied, it > checks pending work and won't do cancel_delayed_work_sync in this boot up > phase.
So, cancel_delayed_work_sync() usually shouldn't be called with irq disabled as it's a possibly blocking call. > The simple calling sequence is like this: > > start_kernel -> of_clk_init -> cpu_clk_init -> pm_qos_add_request(xx, > default_value), > > then pm_qos_update_request. > > I don't know whether it's meaningful to still check pending work here, or > it's not suggested to use pm_qos_update_request in this early boot up phase. > Could you help to share some opinions? (I can fix this issue by adding the > current qos value directly instead of default value, though.) Hmmm... but I suppose this is super-early in the boot. Would it make sense to have a static variable (e.g. bool clk_fully_initailized) to gate the cancel_delayed_sync() call? Thanks. -- tejun
