This is a note to let you know that I've just added the patch titled
drm/bridge: tc358768: Disable non-continuous clock mode
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-bridge-tc358768-disable-non-continuous-clock-mod.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b2d5f4025af48f6cacb05d6613566856e094ecca
Author: Dmitry Osipenko <digetx@xxxxxxxxx>
Date: Sun Oct 3 02:34:46 2021 +0300
drm/bridge: tc358768: Disable non-continuous clock mode
[ Upstream commit fbc5a90e82c1131869e76ce5b082693b8a75c121 ]
Non-continuous clock mode doesn't work because driver doesn't support it
properly. The bridge driver programs wrong bitfields that are required by
the non-continuous mode (BTACNTRL1 register bitfields are swapped in the
code), but fixing them doesn't help.
Display panel of ASUS Transformer TF700T tablet supports non-continuous
mode and display doesn't work at all using that mode. There are no
device-trees that are actively using this DSI bridge in upstream yet,
so clearly the broken mode wasn't ever tested properly. It's a bit too
difficult to get LP mode working, hence let's disable the offending mode
for now and fall back to continuous mode.
Tested-by: Andreas Westman Dorcsak <hedmoo@xxxxxxxxx> # Asus TF700T
Tested-by: Maxim Schwalm <maxim.schwalm@xxxxxxxxx> #TF700T
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
Reviewed-by: Robert Foss <robert.foss@xxxxxxxxxx>
Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20211002233447.1105-5-digetx@xxxxxxxxx
Stable-dep-of: 66962d5c3c51 ("drm/bridge: tc358768: Fix bit updates")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/bridge/tc358768.c b/drivers/gpu/drm/bridge/tc358768.c
index da37dfd81a6fb..1e5304274ce20 100644
--- a/drivers/gpu/drm/bridge/tc358768.c
+++ b/drivers/gpu/drm/bridge/tc358768.c
@@ -637,6 +637,7 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
{
struct tc358768_priv *priv = bridge_to_tc358768(bridge);
struct mipi_dsi_device *dsi_dev = priv->output.dev;
+ unsigned long mode_flags = dsi_dev->mode_flags;
u32 val, val2, lptxcnt, hact, data_type;
s32 raw_val;
const struct drm_display_mode *mode;
@@ -644,6 +645,11 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
u32 dsiclk, dsibclk;
int ret, i;
+ if (mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS) {
+ dev_warn_once(priv->dev, "Non-continuous mode unimplemented, falling back to continuous\n");
+ mode_flags &= ~MIPI_DSI_CLOCK_NON_CONTINUOUS;
+ }
+
tc358768_hw_enable(priv);
ret = tc358768_sw_reset(priv);
@@ -779,7 +785,7 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
val |= BIT(i + 1);
tc358768_write(priv, TC358768_HSTXVREGEN, val);
- if (!(dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
+ if (!(mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
tc358768_write(priv, TC358768_TXOPTIONCNTRL, 0x1);
/* TXTAGOCNT[26:16] RXTASURECNT[10:0] */
@@ -836,7 +842,7 @@ static void tc358768_bridge_pre_enable(struct drm_bridge *bridge)
val |= TC358768_DSI_CONTROL_TXMD;
- if (!(dsi_dev->mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
+ if (!(mode_flags & MIPI_DSI_CLOCK_NON_CONTINUOUS))
val |= TC358768_DSI_CONTROL_HSCKMD;
if (dsi_dev->mode_flags & MIPI_DSI_MODE_NO_EOT_PACKET)
