drm/i915: Add two-stage ILK-style watermark programming (v10)
In addition to calculating final watermarks, let's also pre-calculate a set of intermediate watermark values at atomic check time. These intermediate watermarks are a combination of the watermarks for the old state and the new state; they should satisfy the requirements of both states which means they can be programmed immediately when we commit the atomic state (without waiting for a vblank). Once the vblank does happen, we can then re-program watermarks to the more optimal final value. v2: Significant rebasing/rewriting. v3: - Move 'need_postvbl_update' flag to CRTC state (Daniel) - Don't forget to check intermediate watermark values for validity (Maarten) - Don't due async watermark optimization; just do it at the end of the atomic transaction, after waiting for vblanks. We do want it to be async eventually, but adding that now will cause more trouble for Maarten's in-progress work. (Maarten) - Don't allocate space in crtc_state for intermediate watermarks on platforms that don't need it (gen9+). - Move WaCxSRDisabledForSpriteScaling:ivb into intel_begin_crtc_commit now that ilk_update_wm is gone. v4: - Add a wm_mutex to cover updates to intel_crtc->active and the need_postvbl_update flag. Since we don't have async yet it isn't terribly important yet, but might as well add it now. - Change interface to program watermarks. Platforms will now expose .initial_watermarks() and .optimize_watermarks() functions to do watermark programming. These should lock wm_mutex, copy the appropriate state values into intel_crtc->active, and then call the internal program watermarks function. v5: - Skip intermediate watermark calculation/check during initial hardware readout since we don't trust the existing HW values (and don't have valid values of our own yet). - Don't try to call .optimize_watermarks() on platforms that don't have atomic watermarks yet. (Maarten) v6: - Rebase v7: - Further rebase v8: - A few minor indentation and line length fixes v9: - Yet another rebase since Maarten's patches reworked a bunch of the code (wm_pre, wm_post, etc.) that this was previously based on. v10: - Move wm_mutex to dev_priv to protect against racing commits against disjoint CRTC sets. (Maarten) - Drop unnecessary clearing of cstate->wm.need_postvbl_update (Maarten) Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Signed-off-by: NMatt Roper <matthew.d.roper@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/1452108870-24204-1-git-send-email-matthew.d.roper@intel.comSigned-off-by: NMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
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