From 2fbc487df6e6927bc0a0092f86d4d15961e070de Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 6 Sep 2016 14:50:47 +0200 Subject: pwm: meson: Handle unknown ID values When building with -Wmaybe-uninitialized, we get a couple of harmless warnings about three functions in this new driver that don't look safe to the compiler: drivers/pwm/pwm-meson.c: In function 'meson_pwm_get_state': drivers/pwm/pwm-meson.c:355:26: error: 'mask' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/pwm/pwm-meson.c: In function 'meson_pwm_disable': drivers/pwm/pwm-meson.c:263:13: error: 'enable' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/pwm/pwm-meson.c: In function 'meson_pwm_apply': drivers/pwm/pwm-meson.c:231:13: error: 'clk_shift' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/pwm/pwm-meson.c:231:36: error: 'enable' may be used uninitialized in this function [-Werror=maybe-uninitialized] drivers/pwm/pwm-meson.c:231:24: error: 'clk_enable' may be used uninitialized in this function [-Werror=maybe-uninitialized] Specifically, if we have a device with an ID other than 0 or 1, this would result in undefined behavior. This is currently not possible, but the compiler cannot be expected to know this. This patch adds a 'default' clause to let the compiler know what to do instead, which shuts up the warning and makes the code slightly more resiliant in case it gets extended to other identifiers. Signed-off-by: Arnd Bergmann Acked-by: Neil Armstrong Signed-off-by: Thierry Reding --- drivers/pwm/pwm-meson.c | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'drivers/pwm') diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index bfbbe7f3cdc1..381871b2bb46 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -245,6 +245,9 @@ static void meson_pwm_enable(struct meson_pwm *meson, enable = MISC_B_EN; offset = REG_PWM_B; break; + + default: + return; } value = readl(meson->base + REG_MISC_AB); @@ -273,6 +276,9 @@ static void meson_pwm_disable(struct meson_pwm *meson, unsigned int id) case 1: enable = MISC_B_EN; break; + + default: + return; } value = readl(meson->base + REG_MISC_AB); @@ -352,6 +358,9 @@ static void meson_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, case 1: mask = MISC_B_EN; break; + + default: + return; } value = readl(meson->base + REG_MISC_AB); -- cgit v1.2.3