On 04/21, Luck, Tony wrote: > On Fri, Apr 21, 2017 at 02:35:51PM -0600, Vishal Verma wrote: > > On 04/21, Luck, Tony wrote: > > > Needs extra parentheses to make it right. Vishal, sorry I led you astray. > > > > > > if (!((mce->status & 0xef80) == BIT(7))) > > > > Is this still right though? Anything AND'ed with 0xef80 will never equal > > BIT(7) which is simply 01000000 binary (the lowest byte of the left hand > > side is '0') > > I think so ... here it is in binary > > ef80 = 1110 1111 1000 0000 > BIT7 = 0000 0000 1000 0000 > > so the "&" will zap bits {6:0} and bit {12} [and everything not part > of the MCACOD field]. > > If mce->status had some bit above BIT(7) set, it won't be zapped, so we > won't match the exact value BIT(7). Ah, you're right, I was off by one, taking BIT(7) to mean 0100 0000 > > -Tony