Re: [PATCH v2 1/1] drm/panel: st7703: Fix timings when entering/exiting sleep

From: Guido Günther
Date: Sun Oct 15 2023 - 08:50:18 EST


Hi,
On Mon, Feb 13, 2023 at 01:32:38PM +0100, Frank Oltmanns wrote:
> Fix flickering of the pinephone's XDB599 panel that happens after
> resume.
>
> Extend the delay after issuing the command to exit sleep mode from 60 to
> 120 msec as per the controller's specification.
>
> Introduce a 120 msec delay after issuing the command to enter sleep
> mode. This is needed in order for the controller to reliably finalize
> the sleep in sequence before switching of power supply.
>
> In contrast to the JH057N panel, the XBD599 panel does not require a 20
> msec delay after initialization and exiting sleep mode. Therefore, move
> the delay into the already existing device specific initialization
> function.
>
> The XDB599 does not require a 20 msec delay between the SETBGP and
> SETVCOM commands. Therefore, remove the delay from the device specific
> initialization function.

Thanks. Applied to drm-misc-next.
Cheers,
-- Guido

> Signed-off-by: Frank Oltmanns <frank@xxxxxxxxxxxx>
> Cc: Ondrej Jirman <megi@xxxxxx>
> Reported-by: Samuel Holland <samuel@xxxxxxxxxxxx>
> ---
> drivers/gpu/drm/panel/panel-sitronix-st7703.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/panel/panel-sitronix-st7703.c b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> index 6747ca237ced..c49f4ef883fc 100644
> --- a/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> +++ b/drivers/gpu/drm/panel/panel-sitronix-st7703.c
> @@ -126,6 +126,7 @@ static int jh057n_init_sequence(struct st7703 *ctx)
> 0x18, 0x00, 0x09, 0x0E, 0x29, 0x2D, 0x3C, 0x41,
> 0x37, 0x07, 0x0B, 0x0D, 0x10, 0x11, 0x0F, 0x10,
> 0x11, 0x18);
> + msleep(20);
>
> return 0;
> }
> @@ -273,7 +274,6 @@ static int xbd599_init_sequence(struct st7703 *ctx)
> mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETBGP,
> 0x07, /* VREF_SEL = 4.2V */
> 0x07 /* NVREF_SEL = 4.2V */);
> - msleep(20);
>
> mipi_dsi_dcs_write_seq(dsi, ST7703_CMD_SETVCOM,
> 0x2C, /* VCOMDC_F = -0.67V */
> @@ -350,16 +350,14 @@ static int st7703_enable(struct drm_panel *panel)
> return ret;
> }
>
> - msleep(20);
> -
> ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
> if (ret < 0) {
> dev_err(ctx->dev, "Failed to exit sleep mode: %d\n", ret);
> return ret;
> }
>
> - /* Panel is operational 120 msec after reset */
> - msleep(60);
> + /* It takes the controller 120 msec to wake up after sleep. */
> + msleep(120);
>
> ret = mipi_dsi_dcs_set_display_on(dsi);
> if (ret)
> @@ -384,6 +382,9 @@ static int st7703_disable(struct drm_panel *panel)
> if (ret < 0)
> dev_err(ctx->dev, "Failed to enter sleep mode: %d\n", ret);
>
> + /* It takes the controller 120 msec to enter sleep mode. */
> + msleep(120);
> +
> return 0;
> }
>
> --
> 2.39.1
>