drm/i915: Use new CRC debugfs API

The core provides now an ABI to userspace for generation of frame CRCs,
so implement the ->set_crc_source() callback and reuse as much code as
possible with the previous ABI implementation.

When handling the pageflip interrupt, we skip 1 or 2 frames depending on
the HW because they contain wrong values. For the legacy ABI for
generating frame CRCs, this was done in userspace but now that we have a
generic ABI it's better if it's not exposed by the kernel.

v2:
    - Leave the legacy implementation in place as the ABI implementation
      in the core is incompatible with it.
v3:
    - Use the "cooked" vblank counter so we have a whole 32 bits.
    - Make sure we don't mess with the state of the legacy CRC capture
      ABI implementation.
v4:
    - Keep use of get_vblank_counter as in the legacy code, will be
      changed in a followup commit.

v5:
    - Skip first frame or two as it's known that they contain wrong
      data.
    - A few fixes suggested by Emil Velikov.

v6:
    - Rework programming of the HW registers to preserve previous
      behavior.

v7:
    - Address whitespace issue.
    - Added a comment on why in the implementation of the new ABI we
      skip the 1st or 2nd frames.

v9:
    - Add stub for intel_crtc_set_crc_source.

v12:
    - Rebased.
    - Remove stub for intel_crtc_set_crc_source and instead set the
      callback to NULL (Jani Nikula).

v15:
    - Rebased.

Signed-off-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Robert Foss <robert.foss@collabora.com>

irq
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/20170110134305.26326-2-tomeu.vizoso@collabora.com

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index 6b02dac6ea26..84258df3e8f1 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -1880,5 +1880,11 @@ void lspcon_wait_pcon_mode(struct intel_lspcon *lspcon);
 /* intel_pipe_crc.c */
 int intel_pipe_crc_create(struct drm_minor *minor);
 void intel_pipe_crc_cleanup(struct drm_minor *minor);
+#ifdef CONFIG_DEBUG_FS
+int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
+			      size_t *values_cnt);
+#else
+#define intel_crtc_set_crc_source NULL
+#endif
 extern const struct file_operations i915_display_crc_ctl_fops;
 #endif /* __INTEL_DRV_H__ */