On Wed, 14 Feb 2024 at 11:20, Kathiravan Thirumoorthy <quic_kathirav@xxxxxxxxxxx> wrote: > > > > On 1/26/2024 1:35 AM, Andrew Lunn wrote: > > On Mon, Jan 22, 2024 at 11:26:58AM +0530, Kathiravan Thirumoorthy wrote: > >> gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk are > >> enabled by default and it's RCG is properly configured by bootloader. > > > > Which bootloader? Mainline barebox? > > > Thanks for taking time to review the patches. I couldn't get time to > respond back, sorry for the delay. > > I was referring to the U-boot which is delivered as part of the QSDK. I > will call it out explicitly in the next patch. > > > > >> Some of the NSS clocks needs these clocks to be enabled. To avoid > >> these clocks being disabled by clock framework, drop these entries > >> from the clock table and enable it in the driver probe itself. > > > > If they are critical clocks, i would expect a device to reference > > them. The CCF only disabled unused clocks in late_initcall_sync(), > > which means all drivers should of probed and taken a reference on any > > clocks they require. > > > Some of the NSSCC clocks are enabled by bootloaders and CCF disables the > same (because currently there are no consumers for these clocks > available in the tree. These clocks are consumed by the Networking > drivers which are being upstreamed). To access the NSSCC clocks, > gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, gcc_nssnoc_nsscc_clk clocks > needs to be enabled, else system is going to reboot. To prevent this, I > enabled it in probe. > > However looking back, gcc_snoc_nssnoc_clk, gcc_snoc_nssnoc_1_clk, > gcc_nssnoc_nsscc_clk are consumed by the networking drivers only. So is > it okay to drop these clocks from the GCC driver and add it back once > the actual consumer needs it? So that we don't have to enable it in probe. > > Please let me know your thoughts. If there are no in-kernel consumers, there is no need to worry about them at all, nobody is going to access corresponding hardware. If you have out-of-tree modules, you also probably have your out-of-tree overlays. So you can make use of these clocks in your overlay. I don't see a point in dropping the clock if it is going to be readded later. -- With best wishes Dmitry
