From d4f9a053bfe703b699f673f7adb67bae1f3bc01c Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 30 Sep 2024 20:04:10 +0300 Subject: [PATCH] drm/i915: Introduce intel_scanlines_to_usecs() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Introduce intel_scanlines_to_usecs() as a counterpart to intel_usecs_to_scanlines(). We'll have some use for this in DSB code as we want to do relative scanline waits to evade the delayed vblank, but unfortunately DSB can't do relative scanline waits (only absolute). So we'll instead convert the relative scanline count to usec and do a relative usec wait instead (which the DSB knows how to do). Reviewed-by: Animesh Manna Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20240930170415.23841-9-ville.syrjala@linux.intel.com --- drivers/gpu/drm/i915/display/intel_crtc.c | 11 +++++++++++ drivers/gpu/drm/i915/display/intel_crtc.h | 2 ++ 2 files changed, 13 insertions(+) diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c index 3a28d8450a384..8ed8dd5fe4584 100644 --- a/drivers/gpu/drm/i915/display/intel_crtc.c +++ b/drivers/gpu/drm/i915/display/intel_crtc.c @@ -483,6 +483,17 @@ int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode, 1000 * adjusted_mode->crtc_htotal); } +int intel_scanlines_to_usecs(const struct drm_display_mode *adjusted_mode, + int scanlines) +{ + /* paranoia */ + if (!adjusted_mode->crtc_clock) + return 1; + + return DIV_ROUND_UP_ULL(mul_u32_u32(scanlines, adjusted_mode->crtc_htotal * 1000), + adjusted_mode->crtc_clock); +} + /** * intel_pipe_update_start() - start update of a set of display registers * @state: the atomic state diff --git a/drivers/gpu/drm/i915/display/intel_crtc.h b/drivers/gpu/drm/i915/display/intel_crtc.h index a58ecd11bba26..34ffbd2ee1b79 100644 --- a/drivers/gpu/drm/i915/display/intel_crtc.h +++ b/drivers/gpu/drm/i915/display/intel_crtc.h @@ -31,6 +31,8 @@ struct intel_display; int intel_usecs_to_scanlines(const struct drm_display_mode *adjusted_mode, int usecs); +int intel_scanlines_to_usecs(const struct drm_display_mode *adjusted_mode, + int scanlines); void intel_crtc_arm_vblank_event(struct intel_crtc_state *crtc_state); u32 intel_crtc_max_vblank_count(const struct intel_crtc_state *crtc_state); int intel_crtc_init(struct drm_i915_private *dev_priv, enum pipe pipe); -- 2.39.5