On 29/04/2019 12:18, Nicholas Mc Guire wrote: > On Mon, Apr 29, 2019 at 12:00:06PM +0100, Edward Cree wrote: >> Again, a __force cast doesn't seem necessary here. It looks like the >> code is just using the wrong types; if all of src, dst and uncongested >> were __le64 instead of uint64_t, and the last two lines replaced with >> rds_cong_map_updated(map, le64_to_cpu(uncongested)); then the semantics >> would be kept with neither sparse errors nor __force. >> >> __force is almost never necessary and mostly just masks other bugs or >> endianness confusion in the surrounding code. Instead of adding a >> __force, either fix the code to be sparse-clean or leave the sparse >> warning in place so that future developers know there's something not >> right. >> > changing uncongested to __le64 is not an option here - it would only move > the sparse warnings to those other locatoins where the ports that > became uncongested are being or'ed into uncongested. That's why I say to change *src and *dst too. Sparse won't mind the conversion from void * to __le64 * when they're assigned, and the only operations we do on them... > uncongested |= ~(*src) & *dst; > *dst++ = *src++; ... are some bitwise ops on the values (bitwise ops are legal in any endianness) and incrementation of the pointers (which cares only about the pointee size, not type). -Ed
