From 64d69b5daf6fe9b86236d34e57ba8ebf7d84f245 Mon Sep 17 00:00:00 2001 From: Miquel Raynal Date: Fri, 20 May 2022 10:22:21 +0200 Subject: [PATCH] rtc: rzn1: Avoid mixing variables In the ->set_offset() callback, the 'val' variable is used for two different purposes at the same time, which is oviously wrong: - It contains the intermediate value of the SUBU register that must be written at the end of ->set_offset(). - It is used in the middle of the above calculations to poll the CTL2 register for a specific value. Let's introduce a 'ctl2' variable just for the readl_poll_timeout() call and use it there in place of 'var'. In order to avoid mixing those two variables again, let's rename the remaining occurences of 'val' into 'subu' and initialize it to 0 to avoid the uninitialized variable situation reported by Tom Rix and Colin Ian King already. Fixes: be4a11cf98af ("rtc: rzn1: Add oscillator offset support") Reported-by: Tom Rix Reported-by: Colin Ian King Signed-off-by: Miquel Raynal Signed-off-by: Alexandre Belloni Link: https://lore.kernel.org/r/20220520082221.488849-1-miquel.raynal@bootlin.com --- drivers/rtc/rtc-rzn1.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/rtc/rtc-rzn1.c b/drivers/rtc/rtc-rzn1.c index f92d139..1108d98 100644 --- a/drivers/rtc/rtc-rzn1.c +++ b/drivers/rtc/rtc-rzn1.c @@ -272,7 +272,7 @@ static int rzn1_rtc_set_offset(struct device *dev, long offset) struct rzn1_rtc *rtc = dev_get_drvdata(dev); unsigned int steps; int stepsh, stepsl; - u32 val; + u32 subu = 0, ctl2; int ret; /* @@ -288,7 +288,7 @@ static int rzn1_rtc_set_offset(struct device *dev, long offset) if (stepsh >= -0x3E && stepsh <= 0x3E) { /* 1017 ppb per step */ steps = stepsh; - val |= RZN1_RTC_SUBU_DEV; + subu |= RZN1_RTC_SUBU_DEV; } else if (stepsl >= -0x3E && stepsl <= 0x3E) { /* 3051 ppb per step */ steps = stepsl; @@ -300,18 +300,18 @@ static int rzn1_rtc_set_offset(struct device *dev, long offset) return 0; if (steps > 0) { - val |= steps + 1; + subu |= steps + 1; } else { - val |= RZN1_RTC_SUBU_DECR; - val |= (~(-steps - 1)) & 0x3F; + subu |= RZN1_RTC_SUBU_DECR; + subu |= (~(-steps - 1)) & 0x3F; } - ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, val, - !(val & RZN1_RTC_CTL2_WUST), 100, 2000000); + ret = readl_poll_timeout(rtc->base + RZN1_RTC_CTL2, ctl2, + !(ctl2 & RZN1_RTC_CTL2_WUST), 100, 2000000); if (ret) return ret; - writel(val, rtc->base + RZN1_RTC_SUBU); + writel(subu, rtc->base + RZN1_RTC_SUBU); return 0; } -- 2.7.4