Hi Greg,
On 11/10/2019 05:55, Greg KH wrote:
On Thu, Oct 10, 2019 at 02:19:43PM +0100, Suzuki K Poulose wrote:
A signed feature value is truncated to turn to an unsigned value
causing bad state in the system wide infrastructure. This affects
the discovery of FP/ASIMD support on arm64. Fix this by making sure
we cast it properly.
This was inadvertently fixed upstream in v4.6 onwards with the following :
commit 28c5dcb22f90113dea ("arm64: Rename cpuid_feature field extract routines")
What prevents us from just taking that commit instead? You did not
document that here at all, which I thought I asked for.
Sorry, I missed that part. So, that change introduces helpers to
extract feature fields based on the sign. And it also depends on
commit ff96f7bc7bf6 ("arm64: capabilities: Handle sign of the feature bit")
which introduces "sign" bit for the "capability" list and modifies
the generic capability->matches() helpers to use the hint to switch to the
appropriate helpers.
I could backport parts of the commit 28c5dcb22f90 dropping the bits
that affect the changes mentioned above.
Also, you only need 12 digits for a sha1, 28c5dcb22f90 ("arm64: Rename
cpuid_feature field extract routines") would be just fine :)
Yea, I understand. Its simply a pain to count the numbers, so I make sure
to pickup something that looks larger than the 12 ;-). I will try to stick
to that :-)
Cheers
Suzuki
