Switch to u64 arithmetic and use DIV_ROUND_CLOSEST_ULL() to avoid
the overflow.
buffer[i] is unsigned int and is limited by the lirc core to
IR_MAX_DURATION, which is 500000.
idata->freq is u32, which has a max value of 0xFFFFFFFF.
In the case where buffer[i] is 500000, idata->freq overflows the u32
multiplication for any values >= 8590.
0xFFFFFFFF / 500000 ~= 8589
By casting buffer[i] to u64, idata->freq can be any u32 value without
overflowing the multiplication.
0xFFFFFFFFFFFFFFFF / 500000 ~= 36893488147419 (> 4294967295)
The result of the final operation will fit back into the unsigned int
limits without any issues.
500000 * 0xFFFFFFFF / 1000000 = 0x80000000 (< 0xFFFFFFFF)
Signed-off-by: Cosmin Tanislav <demonsingur@gmail.com>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
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