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() > 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 -- Chris Wilson, Intel Open Source Technology Centre _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
