From b6685c30d15cd7f28c40b2daaeacc00f21b2f12a Mon Sep 17 00:00:00 2001 From: Pengpeng Hou Date: Sun, 20 Sep 2026 11:41:24 +0800 Subject: [PATCH] clk: si5351: fail prepare when PLL reset times out The clock prepare path requests a PLL reset when the platform data requires a deterministic output phase. The reset helper logs polling errors but returns no status, so prepare still enables the output and reports success when the reset did not complete. Return the poll result to prepare, restore the output power-down bit on failure, and leave the output disabled. XTAL and CLKIN inputs continue to bypass PLL reset successfully. The issue was found by our static-analysis tool. Fixes: 5142cbcea324 ("clk: si5351: Wait for bit clear after PLL reset") Reviewed-by: Brian Masney Assisted-by: gpt 5 Signed-off-by: Pengpeng Hou Signed-off-by: Brian Masney --- drivers/clk/clk-si5351.c | 20 ++++++++++++++++---- 1 file changed, 16 insertions(+), 4 deletions(-) diff --git a/drivers/clk/clk-si5351.c b/drivers/clk/clk-si5351.c index 20b0c3c48b86..70daba62305c 100644 --- a/drivers/clk/clk-si5351.c +++ b/drivers/clk/clk-si5351.c @@ -907,7 +907,7 @@ static int _si5351_clkout_set_disable_state( return 0; } -static void _si5351_clkout_reset_pll(struct si5351_driver_data *drvdata, int num) +static int _si5351_clkout_reset_pll(struct si5351_driver_data *drvdata, int num) { u8 val = si5351_reg_read(drvdata, SI5351_CLK0_CTRL + num); u8 mask = val & SI5351_CLK_PLL_SELECT ? SI5351_PLL_RESET_B : @@ -918,7 +918,7 @@ static void _si5351_clkout_reset_pll(struct si5351_driver_data *drvdata, int num switch (val & SI5351_CLK_INPUT_MASK) { case SI5351_CLK_INPUT_XTAL: case SI5351_CLK_INPUT_CLKIN: - return; /* pll not used, no need to reset */ + return 0; /* pll not used, no need to reset */ } si5351_reg_write(drvdata, SI5351_PLL_RESET, mask); @@ -931,6 +931,8 @@ static void _si5351_clkout_reset_pll(struct si5351_driver_data *drvdata, int num dev_dbg(&drvdata->client->dev, "%s - %s: pll = %d\n", __func__, clk_hw_get_name(&drvdata->clkout[num].hw), (val & SI5351_CLK_PLL_SELECT) ? 1 : 0); + + return err; } static int si5351_clkout_prepare(struct clk_hw *hw) @@ -947,8 +949,18 @@ static int si5351_clkout_prepare(struct clk_hw *hw) * Do a pll soft reset on the parent pll -- needed to get a * deterministic phase relationship between the output clocks. */ - if (pdata->clkout[hwdata->num].pll_reset) - _si5351_clkout_reset_pll(hwdata->drvdata, hwdata->num); + if (pdata->clkout[hwdata->num].pll_reset) { + int ret; + + ret = _si5351_clkout_reset_pll(hwdata->drvdata, hwdata->num); + if (ret) { + si5351_set_bits(hwdata->drvdata, + SI5351_CLK0_CTRL + hwdata->num, + SI5351_CLK_POWERDOWN, + SI5351_CLK_POWERDOWN); + return ret; + } + } si5351_set_bits(hwdata->drvdata, SI5351_OUTPUT_ENABLE_CTRL, (1 << hwdata->num), 0);