clk: meson: pll: copy retry workaround from vendor driver

[Heiner Kallweit]

On a S905X4-based system this call fails randomly.
The vendor driver has a retry mechanism and on my system
the second attempt is successful always.

Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
---
 drivers/clk/meson/clk-pll.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index 9e55617bc..daa025b6d 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -320,12 +320,16 @@ static int meson_clk_pll_is_enabled(struct clk_hw *hw)
 
 static int meson_clk_pcie_pll_enable(struct clk_hw *hw)
 {
-	meson_clk_pll_init(hw);
+	int retries = 10;
 
-	if (meson_clk_pll_wait_lock(hw))
-		return -EIO;
+	do {
+		meson_clk_pll_init(hw);
+		if (!meson_clk_pll_wait_lock(hw))
+			return 0;
+		pr_info("Retry enabling PCIe PLL clock\n");
+	} while (--retries);
 
-	return 0;
+	return -EIO;
 }
 
 static int meson_clk_pll_enable(struct clk_hw *hw)
-- 
2.37.2