Messages in this thread | | | Date | Sun, 15 Oct 2023 12:59:22 +0200 | From | Guido Günther <> | Subject | Re: [PATCH 1/1] drm/panel: st7703: Pick different reset sequence |
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Hi, On Sat, Feb 11, 2023 at 06:17:48PM +0100, Frank Oltmanns wrote: > From: Ondrej Jirman <megi@xff.cz> > > 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@xff.cz> > Signed-off-by: Frank Oltmanns <frank@oltmanns.dev> > Reported-by: Samuel Holland <samuel@sholland.org> > --- > drivers/gpu/drm/panel/panel-sitronix-st7703.c | 25 ++++++++++--------- > 1 file changed, 13 insertions(+), 12 deletions(-) > > diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7703.c b/drivers/gpu/drm/panel/panel-sitronix-st7703.c > index 6747ca237ced..45695aa51f62 100644 > --- a/drivers/gpu/drm/panel/panel-sitronix-st7703.c > +++ b/drivers/gpu/drm/panel/panel-sitronix-st7703.c > @@ -411,29 +411,30 @@ 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[] = {
Reviewed-by: Guido Günther <agx@sigxcpu.org>
Cheers, -- Guido
> -- > 2.39.1 >
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