From 541ab84d2b6ea79021d5df0b54d81600334fa2a4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Thu, 24 May 2018 15:54:03 +0300 Subject: drm/i915: Allow DBLSCAN user modes with eDP/LVDS/DSI MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When encountering a connector with the scaling mode property both intel and modesetting ddxs sometimes add tons of DBLSCAN modes to the output's mode list. The idea presumably being that since the output will be going through the panel fitter anyway we can pretend to use any kind of mode. Sadly that means we can't reject user modes with the DBLSCAN flag until we know whether we're going to be using the panel's native mode or the user mode directly. Doing otherwise means X clients using xf86vidmode/xrandr will get a protocol error (and often self terminate as a result) when the kernel refuses to use the requested mode with the DBLSCAN flag. To undo the regression we'll move the DBLSCAN checks into the connector->mode_valid() and encoder->compute_config() hooks. Cc: stable@vger.kernel.org Cc: Vito Caputo Reported-by: Vito Caputo Fixes: e995ca0b8139 ("drm/i915: Provide a device level .mode_valid() hook") References: https://lkml.org/lkml/2018/5/21/715 Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20180524125403.23445-1-ville.syrjala@linux.intel.com Reviewed-by: Maarten Lankhorst Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=106804 Tested-by: Arkadiusz Miskiewicz (cherry picked from commit e4dd27aadd205417a2e9ea9902b698a0252ec3a0) Signed-off-by: Jani Nikula --- drivers/gpu/drm/i915/intel_display.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_display.c') diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index dee3a8e659f1..2cc6faa1daa8 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -14469,12 +14469,22 @@ static enum drm_mode_status intel_mode_valid(struct drm_device *dev, const struct drm_display_mode *mode) { + /* + * Can't reject DBLSCAN here because Xorg ddxen can add piles + * of DBLSCAN modes to the output's mode list when they detect + * the scaling mode property on the connector. And they don't + * ask the kernel to validate those modes in any way until + * modeset time at which point the client gets a protocol error. + * So in order to not upset those clients we silently ignore the + * DBLSCAN flag on such connectors. For other connectors we will + * reject modes with the DBLSCAN flag in encoder->compute_config(). + * And we always reject DBLSCAN modes in connector->mode_valid() + * as we never want such modes on the connector's mode list. + */ + if (mode->vscan > 1) return MODE_NO_VSCAN; - if (mode->flags & DRM_MODE_FLAG_DBLSCAN) - return MODE_NO_DBLESCAN; - if (mode->flags & DRM_MODE_FLAG_HSKEW) return MODE_H_ILLEGAL; -- cgit v1.2.3