From bb72e1dbae0e759252fcdb4a97917200e165bf91 Mon Sep 17 00:00:00 2001 From: Uwe Kleine-König Date: Mon, 16 Nov 2020 10:08:04 +0100 Subject: pwm: keembay: Fix build failure with -Os MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The driver used this construct: #define KMB_PWM_LEADIN_MASK GENMASK(30, 0) static inline void keembay_pwm_update_bits(struct keembay_pwm *priv, u32 mask, u32 val, u32 offset) { u32 buff = readl(priv->base + offset); buff = u32_replace_bits(buff, val, mask); writel(buff, priv->base + offset); } ... keembay_pwm_update_bits(priv, KMB_PWM_LEADIN_MASK, 0, KMB_PWM_LEADIN_OFFSET(pwm->hwpwm)); With CONFIG_CC_OPTIMIZE_FOR_SIZE the compiler (here: gcc 10.2.0) this triggers: In file included from /home/uwe/gsrc/linux/drivers/pwm/pwm-keembay.c:16: In function ‘field_multiplier’, inlined from ‘keembay_pwm_update_bits’ at /home/uwe/gsrc/linux/include/linux/bitfield.h:124:17: /home/uwe/gsrc/linux/include/linux/bitfield.h:119:3: error: call to ‘__bad_mask’ declared with attribute error: bad bitfield mask 119 | __bad_mask(); | ^~~~~~~~~~~~ In function ‘field_multiplier’, inlined from ‘keembay_pwm_update_bits’ at /home/uwe/gsrc/linux/include/linux/bitfield.h:154:1: /home/uwe/gsrc/linux/include/linux/bitfield.h:119:3: error: call to ‘__bad_mask’ declared with attribute error: bad bitfield mask 119 | __bad_mask(); | ^~~~~~~~~~~~ The compiler doesn't seem to be able to notice that with field being 0x3ffffff the expression if ((field | (field - 1)) & ((field | (field - 1)) + 1)) __bad_mask(); can be optimized away. So use __always_inline and document the problem in a comment to fix this. Reported-by: kernel test robot Signed-off-by: Uwe Kleine-König Tested-by: Vijayakannan Ayyathurai Signed-off-by: Thierry Reding --- drivers/pwm/pwm-keembay.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'drivers/pwm/pwm-keembay.c') diff --git a/drivers/pwm/pwm-keembay.c b/drivers/pwm/pwm-keembay.c index 2b6dd070daa4..cdfdef66ff8e 100644 --- a/drivers/pwm/pwm-keembay.c +++ b/drivers/pwm/pwm-keembay.c @@ -63,7 +63,12 @@ static int keembay_clk_enable(struct device *dev, struct clk *clk) return devm_add_action_or_reset(dev, keembay_clk_unprepare, clk); } -static inline void keembay_pwm_update_bits(struct keembay_pwm *priv, u32 mask, +/* + * With gcc 10, CONFIG_CC_OPTIMIZE_FOR_SIZE and only "inline" instead of + * "__always_inline" this fails to compile because the compiler doesn't notice + * for all valid masks (e.g. KMB_PWM_LEADIN_MASK) that they are ok. + */ +static __always_inline void keembay_pwm_update_bits(struct keembay_pwm *priv, u32 mask, u32 val, u32 offset) { u32 buff = readl(priv->base + offset); -- cgit v1.2.3-70-g09d2