[PATCH v3 3/3] clk: qcom: alpha-pll: Check Lucid Ole PLL status before configuring

From: Esteban Urrutia <[email protected]>

On some platforms such as SM8475, not doing this may result in graphical
glitches when the mdss driver takes over.
This fixes the aforementioned issue.

Fixes: 3132a9a11e57 ("clk: qcom: clk-alpha-pll: Add support for lucid ole pll configure")
Signed-off-by: Esteban Urrutia <[email protected]>
---
 drivers/clk/qcom/clk-alpha-pll.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/clk/qcom/clk-alpha-pll.c b/drivers/clk/qcom/clk-alpha-pll.c
index f8313f9d0e30..60173b076cc5 100644
--- a/drivers/clk/qcom/clk-alpha-pll.c
+++ b/drivers/clk/qcom/clk-alpha-pll.c
@@ -2373,6 +2373,15 @@ void clk_lucid_ole_pll_configure(struct clk_alpha_pll *pll, struct regmap *regma
 {
 	u32 lval = config->l;
 
+	/*
+	 * If the bootloader left the PLL enabled it's likely that there are
+	 * RCGs that will lock up if we disable the PLL below.
+	 */
+	if (trion_pll_is_enabled(pll, regmap)) {
+		pr_debug("Lucid Ole PLL is already enabled, skipping configuration\n");
+		return;
+	}
+
 	lval |= TRION_PLL_CAL_VAL << LUCID_EVO_PLL_CAL_L_VAL_SHIFT;
 	lval |= TRION_PLL_CAL_VAL << LUCID_OLE_PLL_RINGOSC_CAL_L_VAL_SHIFT;
 	clk_alpha_pll_write_config(regmap, PLL_L_VAL(pll), lval);

-- 
2.55.0