This patch limits the pixel clock to 13.4 MHz - 266 MHz for i.MX6Q
and 13.5 MHz - 270 MHz for i.MX6DL, which is the range documented
in the HDMI Transmitter chapter of the respective reference manuals.
Without this patch, when connected to a monitor capable of 2160p60
modes, dw_hdmi will happily report this mode and the IPU code will
cause a division by zero in ipu_di_config_clock when trying to figure
out how to divide the 264 MHz HSP clock down to ~600 MHz.
Signed-off-by: Philipp Zabel <p.zabel at pengutronix.de>
---
drivers/gpu/drm/imx/dw_hdmi-imx.c | 32 ++++++++++++++++++++++++++++----
1 file changed, 28 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/imx/dw_hdmi-imx.c
b/drivers/gpu/drm/imx/dw_hdmi-imx.c
index 121d30c..d25aaef 100644
--- a/drivers/gpu/drm/imx/dw_hdmi-imx.c
+++ b/drivers/gpu/drm/imx/dw_hdmi-imx.c
@@ -136,11 +136,34 @@ static struct drm_encoder_funcs dw_hdmi_imx_encoder_funcs
= {
.destroy = drm_encoder_cleanup,
};
+static enum drm_mode_status imx6q_hdmi_mode_valid(struct drm_connector *con,
+ struct drm_display_mode *mode)
+{
+ if (mode->clock < 13500)
+ return MODE_CLOCK_LOW;
+ if (mode->clock > 266000)
+ return MODE_CLOCK_HIGH;
+
+ return MODE_OK;
+}
+
+static enum drm_mode_status imx6dl_hdmi_mode_valid(struct drm_connector *con,
+ struct drm_display_mode
*mode)
+{
+ if (mode->clock < 13500)
+ return MODE_CLOCK_LOW;
+ if (mode->clock > 270000)
+ return MODE_CLOCK_HIGH;
+
+ return MODE_OK;
+}
+
static struct dw_hdmi_plat_data imx6q_hdmi_drv_data = {
- .mpll_cfg = imx_mpll_cfg,
- .cur_ctr = imx_cur_ctr,
- .sym_term = imx_sym_term,
- .dev_type = IMX6Q_HDMI,
+ .mpll_cfg = imx_mpll_cfg,
+ .cur_ctr = imx_cur_ctr,
+ .sym_term = imx_sym_term,
+ .dev_type = IMX6Q_HDMI,
+ .mode_valid = imx6q_hdmi_mode_valid,
};
static struct dw_hdmi_plat_data imx6dl_hdmi_drv_data = {
@@ -148,6 +171,7 @@ static struct dw_hdmi_plat_data imx6dl_hdmi_drv_data = {
.cur_ctr = imx_cur_ctr,
.sym_term = imx_sym_term,
.dev_type = IMX6DL_HDMI,
+ .mode_valid = imx6dl_hdmi_mode_valid,
};
static const struct of_device_id dw_hdmi_imx_dt_ids[] = {
--
2.1.4
