From 00c7ded68012c5a6adb0b14635a9aae573eb81c6 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 10 Jul 2024 10:07:52 -0700 Subject: [PATCH] clk: sophgo: Avoid -Wsometimes-uninitialized in sg2042_clk_pll_set_rate() Clang warns (or errors with CONFIG_WERROR=y): drivers/clk/sophgo/clk-sg2042-pll.c:396:6: error: variable 'ret' is used uninitialized whenever 'if' condition is true [-Werror,-Wsometimes-uninitialized] 396 | if (sg2042_pll_enable(pll, 0)) { | ^~~~~~~~~~~~~~~~~~~~~~~~~ drivers/clk/sophgo/clk-sg2042-pll.c:418:9: note: uninitialized use occurs here 418 | return ret; | ^~~ drivers/clk/sophgo/clk-sg2042-pll.c:396:2: note: remove the 'if' if its condition is always false 396 | if (sg2042_pll_enable(pll, 0)) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 397 | pr_warn("Can't disable pll(%s), status error\n", pll->hw.init->name); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 398 | goto out; | ~~~~~~~~~ 399 | } | ~ drivers/clk/sophgo/clk-sg2042-pll.c:393:9: note: initialize the variable 'ret' to silence this warning 393 | int ret; | ^ | = 0 1 error generated. sg2042_pll_enable() only ever returns zero, so this situation cannot happen, but clang does not perform interprocedural analysis, so it cannot know this to avoid the warning. Make it clearer to the compiler by making sg2042_pll_enable() void and eliminate the error handling in sg2042_clk_pll_set_rate(), which clears up the warning, as ret will always be initialized. Fixes: 48cf7e01386e ("clk: sophgo: Add SG2042 clock driver") Signed-off-by: Nathan Chancellor Link: https://lore.kernel.org/r/20240710-clk-sg2042-fix-sometimes-uninitialized-pll_set_rate-v1-1-538fa82dd539@kernel.org Signed-off-by: Stephen Boyd --- drivers/clk/sophgo/clk-sg2042-pll.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/drivers/clk/sophgo/clk-sg2042-pll.c b/drivers/clk/sophgo/clk-sg2042-pll.c index aa142897aa5e..9695e64fc23b 100644 --- a/drivers/clk/sophgo/clk-sg2042-pll.c +++ b/drivers/clk/sophgo/clk-sg2042-pll.c @@ -103,7 +103,7 @@ static inline void sg2042_pll_ctrl_decode(unsigned int reg_value, ctrl->postdiv2 = FIELD_GET(PLLCTRL_POSTDIV2_MASK, reg_value); } -static inline int sg2042_pll_enable(struct sg2042_pll_clock *pll, bool en) +static inline void sg2042_pll_enable(struct sg2042_pll_clock *pll, bool en) { u32 value; @@ -132,8 +132,6 @@ static inline int sg2042_pll_enable(struct sg2042_pll_clock *pll, bool en) value = readl(pll->base + R_PLL_CLKEN_CONTROL); writel(value & (~(1 << pll->shift_enable)), pll->base + R_PLL_CLKEN_CONTROL); } - - return 0; } /** @@ -393,14 +391,13 @@ static int sg2042_clk_pll_set_rate(struct clk_hw *hw, int ret; spin_lock_irqsave(pll->lock, flags); - if (sg2042_pll_enable(pll, 0)) { - pr_warn("Can't disable pll(%s), status error\n", pll->hw.init->name); - goto out; - } + + sg2042_pll_enable(pll, 0); + ret = sg2042_get_pll_ctl_setting(&pctrl_table, rate, parent_rate); if (ret) { pr_warn("%s: Can't find a proper pll setting\n", pll->hw.init->name); - goto out2; + goto out; } value = sg2042_pll_ctrl_encode(&pctrl_table); @@ -408,9 +405,9 @@ static int sg2042_clk_pll_set_rate(struct clk_hw *hw, /* write the value to top register */ writel(value, pll->base + pll->offset_ctrl); -out2: - sg2042_pll_enable(pll, 1); out: + sg2042_pll_enable(pll, 1); + spin_unlock_irqrestore(pll->lock, flags); pr_debug("--> %s: pll_set_rate: val = 0x%x\n",