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David LechnerandGreg Kroah-Hartman
79fe53ed76
[ Upstream commite2c68cea43] Fix several issues with division of negative numbers in the tmp513 driver. The docs on the DIV_ROUND_CLOSEST macro explain that dividing a negative value by an unsigned type is undefined behavior. The driver was doing this in several places, i.e. data->shunt_uohms has type of u32. The actual "undefined" behavior is that it converts both values to unsigned before doing the division, for example: int ret = DIV_ROUND_CLOSEST(-100, 3U); results in ret == 1431655732 instead of -33. Furthermore the MILLI macro has a type of unsigned long. Multiplying a signed long by an unsigned long results in an unsigned long. So, we need to cast both MILLI and data data->shunt_uohms to long when using the DIV_ROUND_CLOSEST macro. Fixes:f07f9d2467("hwmon: (tmp513) Use SI constants from units.h") Fixes:59dfa75e5d("hwmon: Add driver for Texas Instruments TMP512/513 sensor chips.") Signed-off-by: David Lechner <dlechner@baylibre.com> Link: https://lore.kernel.org/r/20250114-fix-si-prefix-macro-sign-bugs-v1-1-696fd8d10f00@baylibre.com [groeck: Drop some continuation lines] Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Sasha Levin <sashal@kernel.org>