On Thu, 14 Jun 2012 19:37:32 +0100 Chris Wilson <chris at chris-wilson.co.uk> wrote: > On Thu, 14 Jun 2012 14:30:52 -0400, Jesse Barnes <jbarnes at virtuousgeek.org> wrote: > > They aren't going anywhere, and probing on DDC can cause the panel to > > blank briefly, so read them up front and cache them for later queries. > > > > v2: fix potential NULL derefs in intel_dp_get_edid_modes and > > intel_dp_get_edid (Jani) > > copy full EDID length, including extension blocks (Takashi) > > free EDID on teardown (Takashi) > > v3: malloc a new EDID buffer that's big enough for the memcpy (Chris) > > > > References: https://bugs.freedesktop.org/show_bug.cgi?id=46856 > > Signed-off-by: Jesse Barnes <jbarnes at virtuousgeek.org> > > --- > > @@ -2121,10 +2124,19 @@ intel_dp_get_edid(struct drm_connector *connector, struct i2c_adapter *adapter) > > { > > struct intel_dp *intel_dp = intel_attached_dp(connector); > > struct edid *edid; > > + int size; > > + > > + if (is_edp(intel_dp) && intel_dp->edid) { > > + size = (intel_dp->edid->extensions + 1) * EDID_LENGTH; > > + edid = kmalloc(size, GFP_KERNEL); > > + if (!edid) > > + return NULL; > > + > > + memcpy(edid, intel_dp->edid, size); > > + return edid; > > + } > > > > - ironlake_edp_panel_vdd_on(intel_dp); > > edid = drm_get_edid(connector, adapter); > > - ironlake_edp_panel_vdd_off(intel_dp, false); > > return edid; > > This makes me a little uneasy, as the wording here makes it sound like > it is possible for us to initiate a DP aux xfer without raising VDD on > the eDP panel. Having made the decision to retreive the EDID for a panel > only once, we should use that result for all future queries i.e. if it > was NULL during init, assume it will be NULL now as well. (I hope nobody > brings out an eDP-to-HDMI dongle!) Oh good call. Now that I'm checking for whether we have a cached edid I should leave the aux toggling in... Thanks, Jesse -- Jesse Barnes, Intel Open Source Technology Center