Re: [Intel-gfx] [PATCH 01/13] drm/i915/mtl: C20 PLL programming

[Andi Shyti <andi.shyti@linux.intel.com>]

Hi Mika,

> +static void intel_c20_pll_program(struct drm_i915_private *i915,
> +				  const struct intel_crtc_state *crtc_state,
> +				  struct intel_encoder *encoder)
> +{
> +	const struct intel_c20pll_state *pll_state = &crtc_state->cx0pll_state.c20;
> +	bool dp = false;
> +	int lane = crtc_state->lane_count == 4 ? INTEL_CX0_BOTH_LANES : INTEL_CX0_LANE0;
> +	bool cntx;
> +	int i;
> +
> +	if (intel_crtc_has_dp_encoder(crtc_state))
> +		dp = true;
> +
> +	/* 1. Read current context selection */
> +	cntx = intel_cx0_read(i915, encoder->port, INTEL_CX0_LANE0, PHY_C20_VDR_CUSTOM_SERDES_RATE) &
> +		PHY_C20_CONTEXT_TOGGLE;
> +
> +	/* 2. If there is a protocol switch from HDMI to DP or vice versa, clear
> +	 * the lane #0 MPLLB CAL_DONE_BANK DP2.0 10G and 20G rates enable MPLLA.
> +	 * Protocol switch is only applicable for MPLLA
> +	 */
> +	if (intel_c20_protocol_switch_valid(encoder)) {
> +		for (i = 0; i < 4; i++)
> +			intel_c20_sram_write(i915, encoder->port, INTEL_CX0_LANE0, RAWLANEAONX_DIG_TX_MPLLB_CAL_DONE_BANK(i), 0);
> +		msleep(4);

can you use usleep_range() here?

Andi