From: Thierry Reding <treding@xxxxxxxxxx>
The SOR found on Tegra SoCs does not support all the rates potentially
advertised by eDP 1.4. Make sure that the rates that are not supported
are filtered out.
Signed-off-by: Thierry Reding <treding@xxxxxxxxxx>
---
drivers/gpu/drm/tegra/sor.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c
index 2023244ad328..9e6a1ab7ef65 100644
--- a/drivers/gpu/drm/tegra/sor.c
+++ b/drivers/gpu/drm/tegra/sor.c
@@ -605,6 +605,30 @@ static struct clk *tegra_clk_sor_pad_register(struct tegra_sor *sor,
return clk;
}
+static void tegra_sor_filter_rates(struct tegra_sor *sor)
+{
+ struct drm_dp_link *link = &sor->link;
+ unsigned int i;
+
+ /* Tegra only supports RBR, HBR and HBR2 */
+ for (i = 0; i < link->num_rates; i++) {
+ switch (link->rates[i]) {
+ case 1620000:
+ case 2700000:
+ case 5400000:
+ break;
+
+ default:
+ DRM_DEBUG_KMS("link rate %lu kHz not supported\n",
+ link->rates[i]);
+ link->rates[i] = 0;
+ break;
+ }
+ }
+
+ drm_dp_link_update_rates(link);
+}
+
static int tegra_sor_power_up_lanes(struct tegra_sor *sor, unsigned int lanes)
{
unsigned long timeout;
@@ -1897,6 +1921,8 @@ static void tegra_sor_edp_enable(struct drm_encoder *encoder)
if (err < 0)
dev_err(sor->dev, "failed to probe eDP link: %d\n", err);
+ tegra_sor_filter_rates(sor);
+
err = drm_dp_link_choose(&sor->link, mode, info);
if (err < 0)
dev_err(sor->dev, "failed to choose link: %d\n", err);
--
2.23.0
