From: Ville Syrjälä Date: Wed, 16 Oct 2024 14:31:28 +0000 (+0300) Subject: drm/i915/pfit: Reject pfit downscaling for GMCH platforms X-Git-Tag: v6.13-rc1~26^2~12^2~85 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=8a22edcbed9b911b7fa2d9e508bed032c0c27ea6;p=linux-block.git drm/i915/pfit: Reject pfit downscaling for GMCH platforms Gen2/3 pfit doesn't support downscaling at all, so reject it. On i965+ downscaling is supported by the hardware (max scale factor < 2.0), but as downscaling increases the effective pixel rate we can't safely allow it unless intel_crtc_compute_pixel_rate() gets fixed. Probably the best solution would be to calculate (at least an apporiximate) pfit destination window and use ilk_pipe_pixel_rate() for all platforms. For now reject downscaling on all gmch platforms. The intel ddx has a similar check for this in userspace, modesetting ddx does not. And presumably wayland compositors also do not make such assumptions in userspace. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20241016143134.26903-4-ville.syrjala@linux.intel.com Acked-by: Jani Nikula --- diff --git a/drivers/gpu/drm/i915/display/intel_panel.c b/drivers/gpu/drm/i915/display/intel_panel.c index fb7def772376..89cac3b3fd02 100644 --- a/drivers/gpu/drm/i915/display/intel_panel.c +++ b/drivers/gpu/drm/i915/display/intel_panel.c @@ -681,6 +681,7 @@ static void i9xx_scale_aspect(struct intel_crtc_state *crtc_state, static int gmch_panel_fitting(struct intel_crtc_state *crtc_state, const struct drm_connector_state *conn_state) { + struct intel_display *display = to_intel_display(crtc_state); struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc); struct drm_i915_private *dev_priv = to_i915(crtc->base.dev); u32 pfit_control = 0, pfit_pgm_ratios = 0, border = 0; @@ -693,6 +694,25 @@ static int gmch_panel_fitting(struct intel_crtc_state *crtc_state, adjusted_mode->crtc_vdisplay == pipe_src_h) goto out; + /* + * TODO: implement downscaling for i965+. Need to account + * for downscaling in intel_crtc_compute_pixel_rate(). + */ + if (adjusted_mode->crtc_hdisplay < pipe_src_w) { + drm_dbg_kms(display->drm, + "[CRTC:%d:%s] pfit horizontal downscaling (%d->%d) not supported\n", + crtc->base.base.id, crtc->base.name, + pipe_src_w, adjusted_mode->crtc_hdisplay); + return -EINVAL; + } + if (adjusted_mode->crtc_vdisplay < pipe_src_h) { + drm_dbg_kms(display->drm, + "[CRTC:%d:%s] pfit vertical downscaling (%d->%d) not supported\n", + crtc->base.base.id, crtc->base.name, + pipe_src_h, adjusted_mode->crtc_vdisplay); + return -EINVAL; + } + switch (conn_state->scaling_mode) { case DRM_MODE_SCALE_CENTER: /*