On Mon, 11 Nov 2024, Nemesa Garg <nemesa.garg@xxxxxxxxx> wrote:
> It was observed that the first write to DKL PHY DP Mode
> register was not taking effect, hence rewrite this register.
>
> v2: Rename function [Mitul]
>
> Signed-off-by: Nemesa Garg <nemesa.garg@xxxxxxxxx>
> Signed-off-by: Kulkarni, Vandita <vandita.kulkarni@xxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_ddi.c | 15 +++++++++++++++
> 1 file changed, 15 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index 769bd1f26db2..f955d89951b8 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -2104,10 +2104,21 @@ void intel_ddi_sanitize_encoder_pll_mapping(struct intel_encoder *encoder)
> encoder->disable_clock(encoder);
> }
>
> +static void
> +tgl_is_dp_mode_enabled(struct drm_i915_private *dev_priv,
> + enum tc_port tc_port, u32 ln0, u32 ln1)
I went ahead and asked ChatGPT what it thinks of the function name:
If a function's name is tgl_is_dp_mode_enabled(), do you expect it to
return a value, and what would you expect it to return?
It replied:
Yes, based on the function's name, I would expect
`tgl_is_dp_mode_enabled()` to return a value. The naming convention
suggests that it checks whether "DP mode" (perhaps "DisplayPort mode")
is enabled and returns a Boolean value (`true` or `false`).
In this context:
- `tgl_` might be a prefix denoting a specific category or module (e.g.,
"toggle" or "Tiger Lake" if it's hardware-specific).
- `is_` implies a question, typical of Boolean-returning functions.
- `dp_mode_enabled` likely refers to a state or condition ("DisplayPort
mode enabled" in this case).
So, I would expect `tgl_is_dp_mode_enabled()` to return `true` if DP
mode is currently enabled, and `false` otherwise.
> +{
> + if (ln0 != intel_dkl_phy_read(dev_priv, DKL_DP_MODE(tc_port, 0)))
> + intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 0), ln0);
> + if (ln1 != intel_dkl_phy_read(dev_priv, DKL_DP_MODE(tc_port, 1)))
> + intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 1), ln1);
> +}
> +
> static void
> icl_program_mg_dp_mode(struct intel_digital_port *dig_port,
> const struct intel_crtc_state *crtc_state)
> {
> + struct intel_display *display = to_intel_display(crtc_state);
> struct drm_i915_private *dev_priv = to_i915(dig_port->base.base.dev);
> enum tc_port tc_port = intel_encoder_to_tc(&dig_port->base);
> u32 ln0, ln1, pin_assignment;
> @@ -2185,6 +2196,10 @@ icl_program_mg_dp_mode(struct intel_digital_port *dig_port,
> if (DISPLAY_VER(dev_priv) >= 12) {
> intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 0), ln0);
> intel_dkl_phy_write(dev_priv, DKL_DP_MODE(tc_port, 1), ln1);
> + /* WA_14018221282 */
> + if (DISPLAY_VER(display) == 12)
> + tgl_is_dp_mode_enabled(dev_priv, tc_port, ln0, ln1);
> +
> } else {
> intel_de_write(dev_priv, MG_DP_MODE(0, tc_port), ln0);
> intel_de_write(dev_priv, MG_DP_MODE(1, tc_port), ln1);
--
Jani Nikula, Intel
