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Date: Wed, 4 Oct 2017 16:25:50 -0700
From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Matthias Kaehlcke <mka@chromium.org>
Cc: Joe Perches <joe@perches.com>,
        "David S . Miller" <davem@davemloft.net>,
        Simon Horman <simon.horman@netronome.com>,
        Dirk van der Merwe <dirk.vandermerwe@netronome.com>,
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        linux-kernel@vger.kernel.org, Renato Golin <renato.golin@linaro.org>,
        Manoj Gupta <manojgupta@chromium.org>,
        Guenter Roeck <groeck@chromium.org>,
        Doug Anderson <dianders@chromium.org>
Subject: Re: [PATCH] nfp: convert nfp_eth_set_bit_config() into a macro
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On Wed, 4 Oct 2017 16:16:49 -0700, Matthias Kaehlcke wrote:
> > > Thanks for the suggestion. This seems a viable alternative if David
> > > and the NFP owners can live without the extra checking provided by
> > > __BF_FIELD_CHECK.  
> > 
> > The reason the __BF_FIELD_CHECK refuses to compile non-constant masks
> > is that it will require runtime ffs on the mask, which is potentially
> > costly.  I would also feel quite stupid adding those macros to the nfp
> > driver, given that I specifically created the bitfield.h header to not
> > have to reimplement these in every driver I write/maintain.  
> 
> That make sense, thanks for providing more context.
> 
> > Can you please test the patch I provided in the other reply?  
> 
> With this patch there are no errors when building the kernel with
> clang.

Cool, thanks for checking!  I will run it through full tests and queue
for upstreaming :)