On Fri, 2016-09-02 at 19:35 +0200, Knut Omang wrote: > On Fri, 2016-09-02 at 11:10 -0600, Jason Gunthorpe wrote: > > On Fri, Sep 02, 2016 at 06:45:52AM +0200, Knut Omang wrote: > > > On Thu, 2016-09-01 at 20:13 -0600, Jason Gunthorpe wrote: > > > > On Fri, Sep 02, 2016 at 02:09:26AM +0200, Knut Omang wrote: > > > > > This commit removes the implementation and use of the modify_qp_mask > > > > > helper function from the generic OFED implementation and into individual > > > > > device drivers. > > > > > > > > > > Like with use of the ib_modify_qp_is_ok function it should be up to > > > > > each device driver how to handle bits set in the attribute masks. > > > > > > > > > > With the modify_qp_mask function applied in the generic code, > > > > > drivers would not see the bits that the user process actually sets. > > > > > > > > > > The restrictions imposed by the filter are also beyond what > > > > > is imposed by the Infiniband standard, and would also limit > > > > > future drivers or hardware from checking for unsupported or > > > > > invalid settings. > > > > > > > > I'm not excited about this direction. It is not OK for different > > > > drivers to use different mask algorithms, they must all behave the > > > > same. > > > > > > The problem I am solving here is that SIF expects (and requires) some of > > > the bits that the user correctly sets, but that Mellanox either ignore or need to > > > be 0. So when that mask is applied to the user input, the value that reaches > > > the SIF driver is not correct from SIFs perspective. > > > If the values goes through as the ULP sets them, then all is fine. > > > > I guess I still don't understand. SIF and mlx cannot have different > > behavior here. > > Rest assure, being the new kid on the block here, of course we need to > work with existing applications. We try to test with whatever we can get our > hands on, and make sure we behave sensibly.. > > > How is the application writer to know what to do? > > This masking applies to XRC only. > The application does not need to do anything, it treats the XRC QP as any other > RC QP and attempt similar modify_qp operations. > Mlx chooses to ignore some of the bits provided. > > > Can you give a concrete example of the problem? > > Maybe someone from Mellanox can explain the reason > for having the filtering there in the first place, > and only from user mode XRC QPs? Getting some help from git blame here: The modify_qp_mask function was introduced by this commit: 9977f4f64bfeb5d907a793a6880aab2d43b0bed2 by Sean Hefty. Can I ask why this function was introduced, and if it is still needed? Thanks, Knut > > Knut > > > Jason > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
