[PATCH v5 8/9] drm/vc4: hdmi: Limit the BCM2711 to the max without scrambling

[Dave Stevenson]

Hi Maxime

On Mon, 7 Dec 2020 at 15:57, Maxime Ripard <maxime at cerno.tech> wrote:
>
> Unlike the previous generations, the HSM clock limitation is way above
> what we can reach without scrambling, so let's move the maximum
> frequency we support to the maximum clock frequency without scrambling.
>
> Signed-off-by: Maxime Ripard <maxime at cerno.tech>

Reviewed-by: Dave Stevenson <dave.stevenson at raspberrypi.com>

> ---
>  drivers/gpu/drm/vc4/vc4_hdmi.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/vc4/vc4_hdmi.c b/drivers/gpu/drm/vc4/vc4_hdmi.c
> index 5310e06efc82..f4ff6b5db484 100644
> --- a/drivers/gpu/drm/vc4/vc4_hdmi.c
> +++ b/drivers/gpu/drm/vc4/vc4_hdmi.c
> @@ -82,6 +82,8 @@
>  #define CEC_CLOCK_FREQ 40000
>  #define VC4_HSM_MID_CLOCK 149985000
>
> +#define HDMI_14_MAX_TMDS_CLK   (340 * 1000 * 1000)
> +
>  static int vc4_hdmi_debugfs_regs(struct seq_file *m, void *unused)
>  {
>         struct drm_info_node *node = (struct drm_info_node *)m->private;
> @@ -1911,7 +1913,7 @@ static const struct vc4_hdmi_variant bcm2711_hdmi0_variant = {
>         .encoder_type           = VC4_ENCODER_TYPE_HDMI0,
>         .debugfs_name           = "hdmi0_regs",
>         .card_name              = "vc4-hdmi-0",
> -       .max_pixel_clock        = 297000000,
> +       .max_pixel_clock        = HDMI_14_MAX_TMDS_CLK,
>         .registers              = vc5_hdmi_hdmi0_fields,
>         .num_registers          = ARRAY_SIZE(vc5_hdmi_hdmi0_fields),
>         .phy_lane_mapping       = {
> @@ -1937,7 +1939,7 @@ static const struct vc4_hdmi_variant bcm2711_hdmi1_variant = {
>         .encoder_type           = VC4_ENCODER_TYPE_HDMI1,
>         .debugfs_name           = "hdmi1_regs",
>         .card_name              = "vc4-hdmi-1",
> -       .max_pixel_clock        = 297000000,
> +       .max_pixel_clock        = HDMI_14_MAX_TMDS_CLK,
>         .registers              = vc5_hdmi_hdmi1_fields,
>         .num_registers          = ARRAY_SIZE(vc5_hdmi_hdmi1_fields),
>         .phy_lane_mapping       = {
> --
> 2.28.0
>