Commit 525a4f93 authored by Paulo Zanoni's avatar Paulo Zanoni Committed by Daniel Vetter

drm/i915/fbc: add comments to the FBC auxiliary structs

I wrote this code an year and a half ago and I couldn't exactly
remember the main differences of these two structures when reviewing a
new FBC patch. Add some comments to help explain what's the purpose of
each struct.

For the record, the original commits are:
 b183b3f1 ("drm/i915/fbc: introduce struct intel_fbc_reg_params")
 aaf78d27 ("drm/i915/fbc: introduce struct intel_fbc_state_cache")

Cc: Praveen Paneri <praveen.paneri@intel.com>
Signed-off-by: default avatarPaulo Zanoni <paulo.r.zanoni@intel.com>
Reviewed-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170714193822.12121-1-paulo.r.zanoni@intel.comSigned-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 746a5173
...@@ -1058,6 +1058,11 @@ struct intel_fbc { ...@@ -1058,6 +1058,11 @@ struct intel_fbc {
bool underrun_detected; bool underrun_detected;
struct work_struct underrun_work; struct work_struct underrun_work;
/*
* Due to the atomic rules we can't access some structures without the
* appropriate locking, so we cache information here in order to avoid
* these problems.
*/
struct intel_fbc_state_cache { struct intel_fbc_state_cache {
struct i915_vma *vma; struct i915_vma *vma;
...@@ -1079,6 +1084,13 @@ struct intel_fbc { ...@@ -1079,6 +1084,13 @@ struct intel_fbc {
} fb; } fb;
} state_cache; } state_cache;
/*
* This structure contains everything that's relevant to program the
* hardware registers. When we want to figure out if we need to disable
* and re-enable FBC for a new configuration we just check if there's
* something different in the struct. The genx_fbc_activate functions
* are supposed to read from it in order to program the registers.
*/
struct intel_fbc_reg_params { struct intel_fbc_reg_params {
struct i915_vma *vma; struct i915_vma *vma;
......
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