Hi Anand, On Fri, Oct 18, 2019 at 4:04 PM Anand Moon <linux.amoon@xxxxxxxxx> wrote: [...] > > Next step it to try narrow down the clock causing the issue. > > Remove clk_ignore_unused from the command line and add CLK_INGORE_UNUSED > > to the flag of some clocks your clock controller (g12a I think) until > > > > The peripheral clock gates already have this flag (something we should > > fix someday) so don't bother looking there. > > > > Most likely the source of the pwm is getting disabled between the > > late_init call and the probe of the PWM module. Since the pwm is already > > active (w/o a driver), gating the clock source shuts dowm the power to > > the cores. > > > > Looking a the possible inputs in pwm driver, I'd bet on fdiv4. > > > > I had give this above steps a try but with little success. > I am still looking into this much close. it's not clear to me if you have only tested with the PWM and/or FCLK_DIV4 clocks. can you please describe what you have tested so far? for reference - my way of debugging this in the past was: 1. add some printks to clk_disable_unused_subtree (right after the clk_core_is_enabled check) to see which clocks are being disabled 2. add CLK_IGNORE_UNUSED or CLK_IS_CRITICAL to the clocks which are being disabled based on the information from step #1 3. (at some point I had a working kernel with lots of clocks with CLK_IGNORE_UNUSED/CLK_IS_CRITICAL) 4. start dropping the CLK_IGNORE_UNUSED/CLK_IS_CRITICAL flags again until you have traced it down to the clocks that are the actual issue (so far I always had only one clock which caused issues, but it may be multiple) 5. investigate (and/or ask on the mailing list, Amlogic developers are reading the mails here as well) for the few clocks from step #4 > Well I am not the expert in clk or bus configuration. > but after looking into the datasheet of for clk configuration > I found some bus are not configured correctly. did you find any reason which indicates that the problem is related to a bus? the issues I had were due to clocks not being assigned to their consumers in .dts - that can be anything (from a bus to something different). Martin
