> On Thu, 15 Feb 2018 23:59:24 +0100, Lorenzo Bianconi wrote: >> Introduce __mt7601u_rr and __mt7601u_vendor_single_wr routines in order >> to make mt7601u_rmw and mt7601u_rmc atomic since it is possible that >> read and write accesses of mt7601u_rmw/mt7601u_rmc can be interleaved >> with a different write operation on the same register. >> Moreover move write trace point in __mt7601u_vendor_single_wr >> >> Signed-off-by: Lorenzo Bianconi <[email protected]> > > Could you provide an example of which accesses make it problematic? > Is this fixing an actual bug?
Hi Jakub, it is not an issue I had experimented, I noticed a theoretical race reviewing the code. AFAIU, based on the current implementation it is possible that mt7601u_rmw (with mt7601u_rr) loads data from given register but its store access (mt7601u_wr) is preceded by another mt7601u_wr on the same register. In this case the value configured by the first mt7601u_wr executed is overwritten by the second one (the store from mt7601u_rmw) even if the first write is setting a different subfield respect to mt7601u_rmw. Regards, Lorenzo
