phy: sparx5-serdes: add skip_cmu_cfg check when configuring lanes

Add a check for skip_cmu_cfg when configuring the serdes lane.  All
individual serdeses are reset upon first configuration. Resetting the
serdes involves reconfiguring it with preset values. The serdesmode is
required to determine the clock-providing CMU, therefore make sure the
serdes is not reconfigured if the serdesmode is not set.
Signed-off-by: Daniel Machon <daniel.machon@microchip.com>
Link: https://lore.kernel.org/r/20230417180335.2787494-8-daniel.machon@microchip.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/microchip/sparx5_serdes.c

@@ -1646,6 +1646,10 @@ static int sparx5_sd10g28_apply_params(struct sparx5_serdes_macro *macro,
 	u32 value, cmu_idx;
 	int err;
 
+	/* Do not configure serdes if CMU is not to be configured too */
+	if (params->skip_cmu_cfg)
+		return 0;
+
 	cmu_idx = sparx5_serdes_cmu_get(params->cmu_sel, lane_index);
 	err = sparx5_cmu_cfg(priv, cmu_idx);
 	if (err)
@@ -2111,6 +2115,7 @@ static int sparx5_sd10g28_config(struct sparx5_serdes_macro *macro, bool reset)
 		.rxinvert = 1,
 		.txswing = 240,
 		.reg_rst = reset,
+		.skip_cmu_cfg = reset,
 	};
 	int err;