Quoting Taniya Das (2019-01-06 22:26:00) > Hello Stephen, > > On 12/21/2018 2:34 AM, Stephen Boyd wrote: > > Quoting Taniya Das (2018-12-20 03:46:25) > >> The LPASS clocks has a dependency on the GCC lpass clocks to be enabled > >> before accessing them and that was the reason to mark the gcc lpass clocks > >> as critical. But in the case where the lpass subsystem would require a > >> restart, toggling the lpass reset would from HW clear the SW enable bits > >> of the GCC lpass clocks. Thus the next time bringing up the lpass subsystem > >> out of reset would fail. > >> > >> Allow the lpass clock driver to enable/disable the gcc lpass clocks and > >> mark the lpass clocks not be accessed during late_init if no client vote. > > > > You need to add more details here. It feels like you wrote the beginning > > of a paragraph and then stopped abruptly, leaving the reader hanging for > > the whole story. Why is late_init important? Why do we need to leave > > them on from the bootloader? What if the bootloader doesn't leave them > > enabled? This is all rather hacky so I'm deeply confused. Does the lpass > > driver need to get these gcc clks and enable/prepare them during probe? > > But then it needs to also allow a reset happen and change the clk state? > > > > I suspect this situation is circling a larger problem where a reset is > > toggled and that changes some clk state without the clk framework > > knowing. There's not much we can do about that besides having some > > mechanism for the clks to know that their state is now out of sync. If > > that can be done on the provider driver side then we should have an > > easier time not needing to write a bunch of framework code to handle > > this. OMAP folks are dealing with the same problems from what I recall. > > > > Hmm, if I mark the CLK_IS_CRITICAL, I don't see a way to handle it in > provider. Please suggest if you think provider could handle it. As far as I know, I'm not suggesting the use of CLK_IS_CRITICAL here. But removing CLK_IS_CRITICAL and relying on some random bootloader behavior also looks wrong. Can you clarify what's going on?
