hz = 1000000/delta;This needs to be on of the do_div family.
Dave.
Hi Dave, I build-tested the patch for both 32-bit and 64-bit x86. If my understanding is correct, since the divisor is 64-bit here, the compiler will do "if (delta > 1000000) hz = 0; else hz = 1000000/(s32)delta" automatically? In general, is this a good thumb-rule to follow - use do_div if the dividend is 64-bit, and normal divide operator if only the divisor is 64-bit?
Tina
On Friday 05 June 2015 00:55:05 Tina Ruchandani wrote:
hz = 1000000/delta;This needs to be on of the do_div family.
Dave.
Hi Dave, I build-tested the patch for both 32-bit and 64-bit x86. If my understanding is correct, since the divisor is 64-bit here, the compiler will do "if (delta > 1000000) hz = 0; else hz = 1000000/(s32)delta" automatically? In general, is this a good thumb-rule to follow - use do_div if the dividend is 64-bit, and normal divide operator if only the divisor is 64-bit?
I got a build error on 32-bit arm now. There is already a check for an overflow of 10 seconds in there (10 million microseconds), so it is safe to do the easiest fix is to cast that microsecond value to a u32.
Arnd
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Arnd Bergmann -
Tina Ruchandani