[PATCH v10 4/7] drm/i915/scaler: Compute scaling factors for pipe scaler

[Mitul Golani]

Compute scaling factors and scaler user for pipe scaler if
particular scaler user is pipe scaler.

--v2:
- Fix typos. [Ankit]
- Remove FIXME tag. [Ankit]
- Should be common hscale, vscale instead of local one to
avoid garbage overwritten.

--v3:
- Separate out max_scaling information. [Ankit]
- Use max_hscale and max_vscale info instead of INT_MAX. [Ankit]

--v4:
- Add Suggested changes reported by Dan Carpenter.

Signed-off-by: Mitul Golani <mitulkumar.ajitkumar.golani at intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal at intel.com>
Reported-by: kernel test robot <lkp at intel.com>
Reported-by: Dan Carpenter <dan.carpenter at linaro.org>
Closes: https://lore.kernel.org/r/202501080440.Cxe0ZHXJ-lkp@intel.com/
---
 drivers/gpu/drm/i915/display/skl_scaler.c | 39 +++++++++++++++++++----
 1 file changed, 32 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/skl_scaler.c b/drivers/gpu/drm/i915/display/skl_scaler.c
index a832cdccd9fa..2e157d8afb75 100644
--- a/drivers/gpu/drm/i915/display/skl_scaler.c
+++ b/drivers/gpu/drm/i915/display/skl_scaler.c
@@ -368,6 +368,8 @@ static int intel_atomic_setup_scaler(struct intel_crtc_state *crtc_state,
 					&crtc_state->scaler_state;
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	u32 mode;
+	int hscale = 0;
+	int vscale = 0;
 
 	if (*scaler_id < 0)
 		*scaler_id = intel_allocate_scaler(scaler_state, crtc);
@@ -416,15 +418,11 @@ static int intel_atomic_setup_scaler(struct intel_crtc_state *crtc_state,
 		mode = SKL_PS_SCALER_MODE_DYN;
 	}
 
-	/*
-	 * FIXME: we should also check the scaler factors for pfit, so
-	 * this shouldn't be tied directly to planes.
-	 */
 	if (plane_state && plane_state->hw.fb) {
 		const struct drm_framebuffer *fb = plane_state->hw.fb;
 		const struct drm_rect *src = &plane_state->uapi.src;
 		const struct drm_rect *dst = &plane_state->uapi.dst;
-		int hscale, vscale, max_vscale, max_hscale;
+		int max_hscale, max_vscale;
 
 		calculate_max_scale(crtc,
 				    intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier),
@@ -448,11 +446,38 @@ static int intel_atomic_setup_scaler(struct intel_crtc_state *crtc_state,
 
 			return -EINVAL;
 		}
+	}
+
+	if (crtc_state->pch_pfit.enabled) {
+		struct drm_rect src;
+		int max_hscale, max_vscale;
+
+		drm_rect_init(&src, 0, 0,
+			      drm_rect_width(&crtc_state->pipe_src) << 16,
+			      drm_rect_height(&crtc_state->pipe_src) << 16);
+
+		calculate_max_scale(crtc, 0, *scaler_id,
+				    &max_hscale, &max_vscale);
 
-		scaler_state->scalers[*scaler_id].hscale = hscale;
-		scaler_state->scalers[*scaler_id].vscale = vscale;
+		hscale = drm_rect_calc_hscale(&src, &crtc_state->pch_pfit.dst,
+					      0, max_hscale);
+		vscale = drm_rect_calc_vscale(&src, &crtc_state->pch_pfit.dst,
+					      0, max_vscale);
+
+		if (hscale < 0 || vscale < 0) {
+			drm_dbg_kms(display->drm,
+				    "Scaler %d doesn't support required pipe scaling\n",
+				    *scaler_id);
+			drm_rect_debug_print("src: ", &src, true);
+			drm_rect_debug_print("dst: ", &crtc_state->pch_pfit.dst, false);
+
+			return -EINVAL;
+		}
 	}
 
+	scaler_state->scalers[*scaler_id].hscale = hscale;
+	scaler_state->scalers[*scaler_id].vscale = vscale;
+
 	drm_dbg_kms(display->drm, "[CRTC:%d:%s] attached scaler id %u.%u to %s:%d\n",
 		    crtc->base.base.id, crtc->base.name,
 		    crtc->pipe, *scaler_id, name, idx);
-- 
2.48.1