Add suffix ULL to constant 10 in order to give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type u64 (64 bits, unsigned). The expression len * 10 * CEC_TIM_DATA_BIT_TOTAL is currently being evaluated using 32-bit arithmetic. Also, remove unnecessary parentheses and add a code comment to make it clear what is the reason of the code change. Addresses-Coverity-ID: 1454996 Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx> --- Changes in v2: - Update subject and changelog to better reflect the proposed code changes. - Add suffix ULL to constant instead of casting a variable. - Remove unncessary parentheses. - Add code comment. drivers/media/platform/vivid/vivid-cec.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/media/platform/vivid/vivid-cec.c b/drivers/media/platform/vivid/vivid-cec.c index b55d278..614787b 100644 --- a/drivers/media/platform/vivid/vivid-cec.c +++ b/drivers/media/platform/vivid/vivid-cec.c @@ -82,8 +82,15 @@ static void vivid_cec_pin_adap_events(struct cec_adapter *adap, ktime_t ts, if (adap == NULL) return; - ts = ktime_sub_us(ts, (CEC_TIM_START_BIT_TOTAL + - len * 10 * CEC_TIM_DATA_BIT_TOTAL)); + + /* + * Suffix ULL on constant 10 makes the expression + * CEC_TIM_START_BIT_TOTAL + 10ULL * len * CEC_TIM_DATA_BIT_TOTAL + * be evaluated using 64-bit unsigned arithmetic (u64), which + * is what ktime_sub_us expects as second argument. + */ + ts = ktime_sub_us(ts, CEC_TIM_START_BIT_TOTAL + + 10ULL * len * CEC_TIM_DATA_BIT_TOTAL); cec_queue_pin_cec_event(adap, false, ts); ts = ktime_add_us(ts, CEC_TIM_START_BIT_LOW); cec_queue_pin_cec_event(adap, true, ts); -- 2.7.4
