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path: root/drivers/gpu/drm/drm_edid.c
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Diffstat (limited to 'drivers/gpu/drm/drm_edid.c')
-rw-r--r--drivers/gpu/drm/drm_edid.c33
1 files changed, 32 insertions, 1 deletions
diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
index d6f16c02afb5..99144f879a4f 100644
--- a/drivers/gpu/drm/drm_edid.c
+++ b/drivers/gpu/drm/drm_edid.c
@@ -37,6 +37,7 @@
#include <drm/drm_edid.h>
#include <drm/drm_encoder.h>
#include <drm/drm_displayid.h>
+#include <drm/drm_scdc_helper.h>
#include "drm_crtc_internal.h"
@@ -3817,13 +3818,43 @@ EXPORT_SYMBOL(drm_default_rgb_quant_range);
static void drm_parse_hdmi_forum_vsdb(struct drm_connector *connector,
const u8 *hf_vsdb)
{
- struct drm_hdmi_info *hdmi = &connector->display_info.hdmi;
+ struct drm_display_info *display = &connector->display_info;
+ struct drm_hdmi_info *hdmi = &display->hdmi;
if (hf_vsdb[6] & 0x80) {
hdmi->scdc.supported = true;
if (hf_vsdb[6] & 0x40)
hdmi->scdc.read_request = true;
}
+
+ /*
+ * All HDMI 2.0 monitors must support scrambling at rates > 340 MHz.
+ * And as per the spec, three factors confirm this:
+ * * Availability of a HF-VSDB block in EDID (check)
+ * * Non zero Max_TMDS_Char_Rate filed in HF-VSDB (let's check)
+ * * SCDC support available (let's check)
+ * Lets check it out.
+ */
+
+ if (hf_vsdb[5]) {
+ /* max clock is 5000 KHz times block value */
+ u32 max_tmds_clock = hf_vsdb[5] * 5000;
+ struct drm_scdc *scdc = &hdmi->scdc;
+
+ if (max_tmds_clock > 340000) {
+ display->max_tmds_clock = max_tmds_clock;
+ DRM_DEBUG_KMS("HF-VSDB: max TMDS clock %d kHz\n",
+ display->max_tmds_clock);
+ }
+
+ if (scdc->supported) {
+ scdc->scrambling.supported = true;
+
+ /* Few sinks support scrambling for cloks < 340M */
+ if ((hf_vsdb[6] & 0x8))
+ scdc->scrambling.low_rates = true;
+ }
+ }
}
static void drm_parse_hdmi_deep_color_info(struct drm_connector *connector,