From 1b0c22e45508ffbd645430e049c52c46bdaad3b4 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 13 Oct 2017 14:12:45 +0200 Subject: [PATCH] regmap: avoid -Wint-in-bool-context warning When we pass the result of a multiplication as the timeout or the delay, we can get a warning from gcc-7: drivers/mmc/host/bcm2835.c:596:149: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context] drivers/mfd/arizona-core.c:247:195: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context] drivers/gpu/drm/sun4i/sun4i_hdmi_i2c.c:49:27: error: '*' in boolean context, suggest '&&' instead [-Werror=int-in-bool-context] The warning is a bit questionable inside of a macro, but this is intentional on the side of the gcc developers. It is also an indication of another problem: we evaluate the timeout and sleep arguments multiple times, which can have undesired side-effects when those are complex expressions. This changes the two regmap variants to use local variables for storing copies of the timeouts. This adds some more type safety, and avoids both the double-evaluation and the gcc warning. Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81484 Link: http://lkml.kernel.org/r/20170726133756.2161367-1-arnd@arndb.de Signed-off-by: Arnd Bergmann Signed-off-by: Mark Brown --- include/linux/regmap.h | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/include/linux/regmap.h b/include/linux/regmap.h index 1e369f0e921d..edad98890b9b 100644 --- a/include/linux/regmap.h +++ b/include/linux/regmap.h @@ -120,22 +120,24 @@ struct reg_sequence { */ #define regmap_read_poll_timeout(map, addr, val, cond, sleep_us, timeout_us) \ ({ \ - ktime_t __timeout = ktime_add_us(ktime_get(), timeout_us); \ + u64 __timeout_us = (timeout_us); \ + unsigned long __sleep_us = (sleep_us); \ + ktime_t __timeout = ktime_add_us(ktime_get(), __timeout_us); \ int __ret; \ - might_sleep_if(sleep_us); \ + might_sleep_if(__sleep_us); \ for (;;) { \ __ret = regmap_read((map), (addr), &(val)); \ if (__ret) \ break; \ if (cond) \ break; \ - if ((timeout_us) && \ + if ((__timeout_us) && \ ktime_compare(ktime_get(), __timeout) > 0) { \ __ret = regmap_read((map), (addr), &(val)); \ break; \ } \ - if (sleep_us) \ - usleep_range(((sleep_us) >> 2) + 1, sleep_us); \ + if (__sleep_us) \ + usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ } \ __ret ?: ((cond) ? 0 : -ETIMEDOUT); \ }) @@ -160,21 +162,23 @@ struct reg_sequence { */ #define regmap_field_read_poll_timeout(field, val, cond, sleep_us, timeout_us) \ ({ \ - ktime_t timeout = ktime_add_us(ktime_get(), timeout_us); \ + u64 __timeout_us = (timeout_us); \ + unsigned long __sleep_us = (sleep_us); \ + ktime_t timeout = ktime_add_us(ktime_get(), __timeout_us); \ int pollret; \ - might_sleep_if(sleep_us); \ + might_sleep_if(__sleep_us); \ for (;;) { \ pollret = regmap_field_read((field), &(val)); \ if (pollret) \ break; \ if (cond) \ break; \ - if (timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \ + if (__timeout_us && ktime_compare(ktime_get(), timeout) > 0) { \ pollret = regmap_field_read((field), &(val)); \ break; \ } \ - if (sleep_us) \ - usleep_range((sleep_us >> 2) + 1, sleep_us); \ + if (__sleep_us) \ + usleep_range((__sleep_us >> 2) + 1, __sleep_us); \ } \ pollret ?: ((cond) ? 0 : -ETIMEDOUT); \ })