Over the year I got plenty of reports of troubles with H6 HDMI signal.
Sometimes monitor flickers, sometimes there was no image at all and
sometimes it didn't play well with AVR.
It turns out there are multiple issues. Patch 1 fixes clock issue,
which didn't adjust parent rate, even if it is allowed to do so. Patch 2
adds polarity config in tcon1. This is seemingly not needed for pre-HDMI2
controllers, although BSP drivers set it accordingly every time. It
turns out that HDMI2 controllers often don't work with monitors if
polarity is not set correctly. Patch 3 always set clock rate for HDMI
controller. Patch 4 fixes H6 HDMI PHY setting. Patch 5 fixes comment and
clock rate limit (wrong reasoning).
Please take a look.
Best regards,
Jernej
Changes from v1:
- collected Chen-Yu tags (except on replaced patch 4)
- Added some comments in patch 2
- Replaced patch 4 (see commit log for explanation)
Jernej Skrabec (5):
clk: sunxi-ng: mp: fix parent rate change flag check
drm/sun4i: tcon: set sync polarity for tcon1 channel
drm/sun4i: dw-hdmi: always set clock rate
drm/sun4i: Fix H6 HDMI PHY configuration
drm/sun4i: dw-hdmi: Fix max. frequency for H6
drivers/clk/sunxi-ng/ccu_mp.c | 2 +-
drivers/gpu/drm/sun4i/sun4i_tcon.c | 25 +++++++++++++++++++++++++
drivers/gpu/drm/sun4i/sun4i_tcon.h | 6 ++++++
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 10 +++-------
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h | 1 -
drivers/gpu/drm/sun4i/sun8i_hdmi_phy.c | 26 +++++++++-----------------
6 files changed, 44 insertions(+), 26 deletions(-)
--
2.30.0
Channel 1 has polarity bits for vsync and hsync signals but driver never
sets them. It turns out that with pre-HDMI2 controllers seemingly there
is no issue if polarity is not set. However, with HDMI2 controllers
(H6) there often comes to de-synchronization due to phase shift. This
causes flickering screen. It's safe to assume that similar issues might
happen also with pre-HDMI2 controllers.
Solve issue with setting vsync and hsync polarity. Note that display
stacks with tcon top have polarity bits actually in tcon0 polarity
register.
Fixes: 9026e0d122ac ("drm: Add Allwinner A10 Display Engine support")
Reviewed-by: Chen-Yu Tsai <[email protected]>
Tested-by: Andre Heider <[email protected]>
Signed-off-by: Jernej Skrabec <[email protected]>
---
drivers/gpu/drm/sun4i/sun4i_tcon.c | 25 +++++++++++++++++++++++++
drivers/gpu/drm/sun4i/sun4i_tcon.h | 6 ++++++
2 files changed, 31 insertions(+)
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.c b/drivers/gpu/drm/sun4i/sun4i_tcon.c
index 6b9af4c08cd6..9f06dec0fc61 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.c
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.c
@@ -672,6 +672,30 @@ static void sun4i_tcon1_mode_set(struct sun4i_tcon *tcon,
SUN4I_TCON1_BASIC5_V_SYNC(vsync) |
SUN4I_TCON1_BASIC5_H_SYNC(hsync));
+ /* Setup the polarity of multiple signals */
+ if (tcon->quirks->polarity_in_ch0) {
+ val = 0;
+
+ if (mode->flags & DRM_MODE_FLAG_PHSYNC)
+ val |= SUN4I_TCON0_IO_POL_HSYNC_POSITIVE;
+
+ if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+ val |= SUN4I_TCON0_IO_POL_VSYNC_POSITIVE;
+
+ regmap_write(tcon->regs, SUN4I_TCON0_IO_POL_REG, val);
+ } else {
+ /* according to vendor driver, this bit must be always set */
+ val = SUN4I_TCON1_IO_POL_UNKNOWN;
+
+ if (mode->flags & DRM_MODE_FLAG_PHSYNC)
+ val |= SUN4I_TCON1_IO_POL_HSYNC_POSITIVE;
+
+ if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+ val |= SUN4I_TCON1_IO_POL_VSYNC_POSITIVE;
+
+ regmap_write(tcon->regs, SUN4I_TCON1_IO_POL_REG, val);
+ }
+
/* Map output pins to channel 1 */
regmap_update_bits(tcon->regs, SUN4I_TCON_GCTL_REG,
SUN4I_TCON_GCTL_IOMAP_MASK,
@@ -1500,6 +1524,7 @@ static const struct sun4i_tcon_quirks sun8i_a83t_tv_quirks = {
static const struct sun4i_tcon_quirks sun8i_r40_tv_quirks = {
.has_channel_1 = true,
+ .polarity_in_ch0 = true,
.set_mux = sun8i_r40_tcon_tv_set_mux,
};
diff --git a/drivers/gpu/drm/sun4i/sun4i_tcon.h b/drivers/gpu/drm/sun4i/sun4i_tcon.h
index c5ac1b02482c..e624f6977eb8 100644
--- a/drivers/gpu/drm/sun4i/sun4i_tcon.h
+++ b/drivers/gpu/drm/sun4i/sun4i_tcon.h
@@ -154,6 +154,11 @@
#define SUN4I_TCON1_BASIC5_V_SYNC(height) (((height) - 1) & 0x3ff)
#define SUN4I_TCON1_IO_POL_REG 0xf0
+/* there is no documentation about this bit */
+#define SUN4I_TCON1_IO_POL_UNKNOWN BIT(26)
+#define SUN4I_TCON1_IO_POL_HSYNC_POSITIVE BIT(25)
+#define SUN4I_TCON1_IO_POL_VSYNC_POSITIVE BIT(24)
+
#define SUN4I_TCON1_IO_TRI_REG 0xf4
#define SUN4I_TCON_ECC_FIFO_REG 0xf8
@@ -236,6 +241,7 @@ struct sun4i_tcon_quirks {
bool needs_de_be_mux; /* sun6i needs mux to select backend */
bool needs_edp_reset; /* a80 edp reset needed for tcon0 access */
bool supports_lvds; /* Does the TCON support an LVDS output? */
+ bool polarity_in_ch0; /* some tcon1 channels have polarity bits in tcon0 pol register */
u8 dclk_min_div; /* minimum divider for TCON0 DCLK */
/* callback to handle tcon muxing options */
--
2.30.0
It turns out that reasoning for lowering max. supported frequency is
wrong. Scrambling works just fine. Several now fixed bugs prevented
proper functioning, even with rates lower than 340 MHz. Issues were just
more pronounced with higher frequencies.
Fix that by allowing max. supported frequency in HW and fix the comment.
Fixes: cd9063757a22 ("drm/sun4i: DW HDMI: Lower max. supported rate for H6")
Reviewed-by: Chen-Yu Tsai <[email protected]>
Tested-by: Andre Heider <[email protected]>
Signed-off-by: Jernej Skrabec <[email protected]>
---
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 23773a5e0650..bbdfd5e26ec8 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -47,11 +47,9 @@ sun8i_dw_hdmi_mode_valid_h6(struct dw_hdmi *hdmi, void *data,
{
/*
* Controller support maximum of 594 MHz, which correlates to
- * 4K@60Hz 4:4:4 or RGB. However, for frequencies greater than
- * 340 MHz scrambling has to be enabled. Because scrambling is
- * not yet implemented, just limit to 340 MHz for now.
+ * 4K@60Hz 4:4:4 or RGB.
*/
- if (mode->clock > 340000)
+ if (mode->clock > 594000)
return MODE_CLOCK_HIGH;
return MODE_OK;
--
2.30.0
As expected, HDMI controller clock should always match pixel clock. In
the past, changing HDMI controller rate would seemingly worsen
situation. However, that was the result of other bugs which are now
fixed.
Fix that by removing set_rate quirk and always set clock rate.
Fixes: 40bb9d3147b2 ("drm/sun4i: Add support for H6 DW HDMI controller")
Reviewed-by: Chen-Yu Tsai <[email protected]>
Tested-by: Andre Heider <[email protected]>
Signed-off-by: Jernej Skrabec <[email protected]>
---
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c | 4 +---
drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h | 1 -
2 files changed, 1 insertion(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
index 92add2cef2e7..23773a5e0650 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.c
@@ -21,8 +21,7 @@ static void sun8i_dw_hdmi_encoder_mode_set(struct drm_encoder *encoder,
{
struct sun8i_dw_hdmi *hdmi = encoder_to_sun8i_dw_hdmi(encoder);
- if (hdmi->quirks->set_rate)
- clk_set_rate(hdmi->clk_tmds, mode->crtc_clock * 1000);
+ clk_set_rate(hdmi->clk_tmds, mode->crtc_clock * 1000);
}
static const struct drm_encoder_helper_funcs
@@ -295,7 +294,6 @@ static int sun8i_dw_hdmi_remove(struct platform_device *pdev)
static const struct sun8i_dw_hdmi_quirks sun8i_a83t_quirks = {
.mode_valid = sun8i_dw_hdmi_mode_valid_a83t,
- .set_rate = true,
};
static const struct sun8i_dw_hdmi_quirks sun50i_h6_quirks = {
diff --git a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
index d983746fa194..d4b55af0592f 100644
--- a/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
+++ b/drivers/gpu/drm/sun4i/sun8i_dw_hdmi.h
@@ -179,7 +179,6 @@ struct sun8i_dw_hdmi_quirks {
enum drm_mode_status (*mode_valid)(struct dw_hdmi *hdmi, void *data,
const struct drm_display_info *info,
const struct drm_display_mode *mode);
- unsigned int set_rate : 1;
unsigned int use_drm_infoframe : 1;
};
--
2.30.0