On Sun, May 3, 2020 at 2:30 PM Chris Wilson chris@chris-wilson.co.uk wrote:
Quoting Jason A. Donenfeld (2020-04-30 23:10:16)
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.
Cc: stable@vger.kernel.org
The same argument as on the previous submission is that we return to the caller if we can't use movntqda as their fallback path should be faster than uncached memcpy.
Oh, THAT's what you meant before. Okay, will follow up.