On Wed, 09 Mar 2016, Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> wrote: > On Wed, Mar 09, 2016 at 05:31:39PM +0200, Imre Deak wrote: >> While working on the CDCLK init code I realized that the driver load time >> dependencies between the different init steps are rather difficult to follow >> and so it's not obvious where some new piece of initialization needs to be >> added. >> >> Also because some things are initialized too late, other steps depending on >> these must be initialized in a non-logical place or even split into multiple >> parts. One example is the CDCLK initialization which needs the display >> callbacks to be set already, but those callbacks are setup only late, so the >> CDCLK initialization must be done in two parts. >> >> As a generic solution, I suggest that we define the following load >> time init phases: >> - state init not requiring device access >> (i.e SW only, like initializing locks, allocating system memory, setting >> up callbacks, device attributes) >> - minimal HW setup to enable MMIO access to the device >> - state init requiring device access w/o side effects >> (i.e. read-only HW access, no interface registrations) >> - state init causing device-wide side effects >> (i.e any HW access, no interface registration) >> - registering all interfaces > > On paper sounds goods. The only complaint I have is that we have only > nomenclature for 2 phases: init and init_hw. To be compelling I want > consistent names for each init function so that we know at a glance what > phase we are in, and the expectations/limitations upon the function. > > init_early() / setup() > init_mmio() > init_late() > init_hw() Agreed. > >> This patchset adds the corresponding comment markers for the first >> two phases above and one common phase for the rest of the current >> init steps. Later we could also add the last three init phases above >> and restructure the code accordingly. >> >> For now I only moved earlier a few obvious init steps that fit these >> new phases. >> >> I smoke tested this on GEN4, SNB, BXT. >> >> Imre Deak (7): >> drm/i915: Add comments marking the start of load time init phases >> drm/i915: Move laod time PCH detect, DPIO, power domain SW init >> earlier >> drm/i915: Move load time IRQ SW init earlier >> drm/i915: Move load time display/audio callback init earlier >> drm/i915: Move load time clock gating callback init earlier >> drm/i915: Move load time runtime device info init earlier >> drm/i915: Move load time runtime PM get later > > Lgtm. > -Chris -- Jani Nikula, Intel Open Source Technology Center _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
