This is a note to let you know that I've just added the patch titled
drm/panel: st7703: Pick different reset sequence
to the 6.6-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-panel-st7703-pick-different-reset-sequence.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 88f108973ce4e80aa453caa87e3da1c9d49effe3
Author: Ondrej Jirman <megi@xxxxxx>
Date: Sat Feb 11 18:17:48 2023 +0100
drm/panel: st7703: Pick different reset sequence
[ Upstream commit d12d635bb03c7cb4830acb641eb176ee9ff2aa89 ]
Switching to a different reset sequence, enabling IOVCC before enabling
VCC.
There also needs to be a delay after enabling the supplies and before
deasserting the reset. The datasheet specifies 1ms after the supplies
reach the required voltage. Use 10-20ms to also give the power supplies
some time to reach the required voltage, too.
This fixes intermittent panel initialization failures and screen
corruption during resume from sleep on panel xingbangda,xbd599 (e.g.
used in PinePhone).
Signed-off-by: Ondrej Jirman <megi@xxxxxx>
Signed-off-by: Frank Oltmanns <frank@xxxxxxxxxxxx>
Reported-by: Samuel Holland <samuel@xxxxxxxxxxxx>
Reviewed-by: Guido Günther <agx@xxxxxxxxxxx>
Tested-by: Guido Günther <agx@xxxxxxxxxxx>
Signed-off-by: Guido Günther <agx@xxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20230211171748.36692-2-frank@xxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7703.c b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
index 6a39456395350..7bb723d445ade 100644
--- a/drivers/gpu/drm/panel/panel-sitronix-st7703.c
+++ b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
@@ -506,29 +506,30 @@ static int st7703_prepare(struct drm_panel *panel)
return 0;
dev_dbg(ctx->dev, "Resetting the panel\n");
- ret = regulator_enable(ctx->vcc);
+ gpiod_set_value_cansleep(ctx->reset_gpio, 1);
+
+ ret = regulator_enable(ctx->iovcc);
if (ret < 0) {
- dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
+ dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
return ret;
}
- ret = regulator_enable(ctx->iovcc);
+
+ ret = regulator_enable(ctx->vcc);
if (ret < 0) {
- dev_err(ctx->dev, "Failed to enable iovcc supply: %d\n", ret);
- goto disable_vcc;
+ dev_err(ctx->dev, "Failed to enable vcc supply: %d\n", ret);
+ regulator_disable(ctx->iovcc);
+ return ret;
}
- gpiod_set_value_cansleep(ctx->reset_gpio, 1);
- usleep_range(20, 40);
+ /* Give power supplies time to stabilize before deasserting reset. */
+ usleep_range(10000, 20000);
+
gpiod_set_value_cansleep(ctx->reset_gpio, 0);
- msleep(20);
+ usleep_range(15000, 20000);
ctx->prepared = true;
return 0;
-
-disable_vcc:
- regulator_disable(ctx->vcc);
- return ret;
}
static const u32 mantix_bus_formats[] = {
