drm/i915: Fix wrong number of HDMI translation entries
authorDamien Lespiau <damien.lespiau@intel.com>
Sat, 9 Aug 2014 15:29:31 +0000 (16:29 +0100)
committerDaniel Vetter <daniel.vetter@ffwll.ch>
Mon, 11 Aug 2014 09:29:29 +0000 (11:29 +0200)
I keep telling myself that those tables aren't great because their size
is the number of dwords we need to program and not the number of entries
(number of dwords = number of entries * 2).

And... I got it wrong when I refactored the code. Fortunately, it was
only wrong when the VBT table (or the code parsing it) is itself
erroneous. Long story short, it shouldn't matter, but still, there's a
potential array overflow and random programming of the DDI translation
tables.

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Damien Lespiau <damien.lespiau@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
drivers/gpu/drm/i915/intel_ddi.c

index ca1f9a8a7d03bf7c41e403e2cbb305b3e91ec327..02d55843c78df627d0c54b2ffc26cc18c6bc4b46 100644 (file)
@@ -169,14 +169,14 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port)
                ddi_translations_dp = bdw_ddi_translations_dp;
                ddi_translations_edp = bdw_ddi_translations_edp;
                ddi_translations_hdmi = bdw_ddi_translations_hdmi;
-               n_hdmi_entries = ARRAY_SIZE(bdw_ddi_translations_hdmi);
+               n_hdmi_entries = ARRAY_SIZE(bdw_ddi_translations_hdmi) / 2;
                hdmi_800mV_0dB = 7;
        } else if (IS_HASWELL(dev)) {
                ddi_translations_fdi = hsw_ddi_translations_fdi;
                ddi_translations_dp = hsw_ddi_translations_dp;
                ddi_translations_edp = hsw_ddi_translations_dp;
                ddi_translations_hdmi = hsw_ddi_translations_hdmi;
-               n_hdmi_entries = ARRAY_SIZE(hsw_ddi_translations_hdmi);
+               n_hdmi_entries = ARRAY_SIZE(hsw_ddi_translations_hdmi) / 2;
                hdmi_800mV_0dB = 6;
        } else {
                WARN(1, "ddi translation table missing\n");
@@ -184,7 +184,7 @@ static void intel_prepare_ddi_buffers(struct drm_device *dev, enum port port)
                ddi_translations_fdi = bdw_ddi_translations_fdi;
                ddi_translations_dp = bdw_ddi_translations_dp;
                ddi_translations_hdmi = bdw_ddi_translations_hdmi;
-               n_hdmi_entries = ARRAY_SIZE(bdw_ddi_translations_hdmi);
+               n_hdmi_entries = ARRAY_SIZE(bdw_ddi_translations_hdmi) / 2;
                hdmi_800mV_0dB = 7;
        }