Re: [RFC/RFT 01/10] i2c: add 'is_suspended' flag for i2c adapters

From: Geert Uytterhoeven
Date: Wed Dec 19 2018 - 04:39:20 EST

Hi Wolfram,

On Wed, Dec 19, 2018 at 12:34 AM Wolfram Sang <wsa@xxxxxxxxxxxxx> wrote:
> > > + unsigned int is_suspended:1; /* owned by the I2C core */
> >
> > When more stuff is added to this bit field (which always happens at
> > some point) updates to all members of the bit field will have to use
> > the same root-adapter-locking, or we will suffer from RMW-races. So
> > this feels like an invitation for future disaster. Maybe a comment
> > about that to remind our future selves? Or perhaps the bit field
> > should be avoided altogether?
> Changed to bool. Thanks!

Does that help, given bool is smaller than the CPUs word size?
Is it Alpha that cannot do atomic operations on bytes?



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds