On 2020-04-30 16:10:16 [-0600], Jason A. Donenfeld wrote: > Sometimes it's not okay to use SIMD registers, the conditions for which > have changed subtly from kernel release to kernel release. Usually the > pattern is to check for may_use_simd() and then fallback to using > something slower in the unlikely case SIMD registers aren't available. > So, this patch fixes up i915's accelerated memcpy routines to fallback > to boring memcpy if may_use_simd() is false. That would indicate that these functions are used from IRQ/softirq which break otherwise if the kernel is also using the registers. The crypto code uses it for that purpose. So Reviewed-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> May I ask how large the memcpy can be? I'm asking in case it is large and an explicit rescheduling point might be needed. > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> Sebastian
