Am Sonntag, 23. Juni 2024, 16:38:34 CEST schrieb Marek Vasut:
> Use tc_pxl_pll_calc() to find out the exact clock frequency generated by the
> Pixel PLL. Use the Pixel PLL frequency as adjusted_mode clock frequency and
> pass it down the display pipeline to obtain exactly this frequency on input
> into this bridge.
>
> The precise input frequency that matches the Pixel PLL frequency is
> important for this bridge, as if the frequencies do not match, the
> bridge does suffer VFIFO overruns or underruns.
>
> Signed-off-by: Marek Vasut <marex@xxxxxxx>
This changes actually changes the media_disp1_pix clock to match the
configured PLL rate in the bridge. 147333000 instead of 148500000.
Reviewed-by: Alexander Stein <alexander.stein@xxxxxxxxxxxxxxx>
> ---
> Cc: Andrzej Hajda <andrzej.hajda@xxxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Jernej Skrabec <jernej.skrabec@xxxxxxxxx>
> Cc: Jonas Karlman <jonas@xxxxxxxxx>
> Cc: Laurent Pinchart <Laurent.pinchart@xxxxxxxxxxxxxxxx>
> Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> Cc: Robert Foss <rfoss@xxxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Cc: kernel@xxxxxxxxxxxxxxxxxx
> ---
> V2: - Use mode clock as input into tc_pxl_pll_calc() to avoid
> accumulating rounding error
> V3: No change
> ---
> drivers/gpu/drm/bridge/tc358767.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> index cbb342d811ac3..20be21660ba76 100644
> --- a/drivers/gpu/drm/bridge/tc358767.c
> +++ b/drivers/gpu/drm/bridge/tc358767.c
> @@ -1619,6 +1619,18 @@ static int tc_dpi_atomic_check(struct drm_bridge *bridge,
> struct drm_crtc_state *crtc_state,
> struct drm_connector_state *conn_state)
> {
> + struct tc_data *tc = bridge_to_tc(bridge);
> + int adjusted_clock = 0;
> + int ret;
> +
> + ret = tc_pxl_pll_calc(tc, clk_get_rate(tc->refclk),
> + crtc_state->mode.clock * 1000,
> + &adjusted_clock, NULL);
> + if (ret)
> + return ret;
> +
> + crtc_state->adjusted_mode.clock = adjusted_clock / 1000;
> +
> /* DSI->DPI interface clock limitation: upto 100 MHz */
> if (crtc_state->adjusted_mode.clock > 100000)
> return -EINVAL;
> @@ -1631,6 +1643,18 @@ static int tc_edp_atomic_check(struct drm_bridge *bridge,
> struct drm_crtc_state *crtc_state,
> struct drm_connector_state *conn_state)
> {
> + struct tc_data *tc = bridge_to_tc(bridge);
> + int adjusted_clock = 0;
> + int ret;
> +
> + ret = tc_pxl_pll_calc(tc, clk_get_rate(tc->refclk),
> + crtc_state->mode.clock * 1000,
> + &adjusted_clock, NULL);
> + if (ret)
> + return ret;
> +
> + crtc_state->adjusted_mode.clock = adjusted_clock / 1000;
> +
> /* DPI->(e)DP interface clock limitation: upto 154 MHz */
> if (crtc_state->adjusted_mode.clock > 154000)
> return -EINVAL;
>
--
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