[PATCH] clk: meson: pll: adjust timeout in meson_clk_pll_wait_lock()

Heiner Kallweit hkallweit1 at gmail.com
Sun Aug 14 14:29:31 PDT 2022


Currently we loop over meson_parm_read() up to 24mln times.
This results in a unpredictable timeout period. In my case
it's over 5s on a S905X4-based system. Make the timeout
period predictable and set it to 100ms.

Whilst we're at it: All callers of this function return -EIO
in case of failure, therefore we can return this value directly
in the timeout case.

Signed-off-by: Heiner Kallweit <hkallweit1 at gmail.com>
---
 drivers/clk/meson/clk-pll.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/drivers/clk/meson/clk-pll.c b/drivers/clk/meson/clk-pll.c
index daa025b6d..d70bee331 100644
--- a/drivers/clk/meson/clk-pll.c
+++ b/drivers/clk/meson/clk-pll.c
@@ -277,17 +277,17 @@ static int meson_clk_pll_wait_lock(struct clk_hw *hw)
 {
 	struct clk_regmap *clk = to_clk_regmap(hw);
 	struct meson_clk_pll_data *pll = meson_clk_pll_data(clk);
-	int delay = 24000000;
+	int delay = 5000;
 
 	do {
-		/* Is the clock locked now ? */
+		/* Is the clock locked now ? Time out after 100ms. */
 		if (meson_parm_read(clk->map, &pll->l))
 			return 0;
 
-		delay--;
-	} while (delay > 0);
+		udelay(20);
+	} while (--delay);
 
-	return -ETIMEDOUT;
+	return -EIO;
 }
 
 static int meson_clk_pll_init(struct clk_hw *hw)
@@ -350,10 +350,7 @@ static int meson_clk_pll_enable(struct clk_hw *hw)
 	/* Take the pll out reset */
 	meson_parm_write(clk->map, &pll->rst, 0);
 
-	if (meson_clk_pll_wait_lock(hw))
-		return -EIO;
-
-	return 0;
+	return meson_clk_pll_wait_lock(hw);
 }
 
 static void meson_clk_pll_disable(struct clk_hw *hw)
-- 
2.37.2




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