This allows the hdmi driver to pick e.g. 64.8MHz instead of 65Mhz when we cannot output the exact frequency, enabling the imx8mp HDMI output to support more modes Signed-off-by: Dominique Martinet <dominique.martinet@xxxxxxxxxxxxxxxxx> --- This completes the patch series sent by Adam Ford here: https://lkml.kernel.org/r/20240904023310.163371-1-aford173@xxxxxxxxx and makes the cheap screens we recommend work with our imx8mp board without further kludging. drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c index 13bc570c5473..9431cd5e06c3 100644 --- a/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c +++ b/drivers/gpu/drm/bridge/imx/imx8mp-hdmi-tx.c @@ -23,6 +23,7 @@ imx8mp_hdmi_mode_valid(struct dw_hdmi *dw_hdmi, void *data, const struct drm_display_mode *mode) { struct imx8mp_hdmi *hdmi = (struct imx8mp_hdmi *)data; + long round_rate; if (mode->clock < 13500) return MODE_CLOCK_LOW; @@ -30,8 +31,9 @@ imx8mp_hdmi_mode_valid(struct dw_hdmi *dw_hdmi, void *data, if (mode->clock > 297000) return MODE_CLOCK_HIGH; - if (clk_round_rate(hdmi->pixclk, mode->clock * 1000) != - mode->clock * 1000) + round_rate = clk_round_rate(hdmi->pixclk, mode->clock * 1000); + /* accept 0.5% = 1/200 = 5/1000 tolerance */ + if (abs(round_rate - mode->clock * 1000) > mode->clock * 5) return MODE_CLOCK_RANGE; /* We don't support double-clocked and Interlaced modes */ -- 2.39.2
