Re: [PATCH 2/2] nvmem: iomap: new driver exposing NVMEM accessible using I/O mapping

[Rafał Miłecki]

On 05.03.2021 11:33, Srinivas Kandagatla wrote:
> On 05/03/2021 10:24, Rafał Miłecki wrote:
> > > > +static int iomap_read(void *context, unsigned int offset, void *val,
> > > > +              size_t bytes)
> > > > +{
> > > > +    struct iomap *priv = context;
> > > > +    u8 *src = priv->base + offset;
> > > > +    u8 *dst = val;
> > > > +    size_t tmp;
> > > > +
> > > > +    tmp = offset % 4;
> > > > +    memcpy_fromio(dst, src, tmp);
> > > > +    dst += tmp;
> > > > +    src += tmp;
> > > > +    bytes -= tmp;
> > > > +
> > > > +    tmp = rounddown(bytes, 4);
> > > > +    __ioread32_copy(dst, src, tmp / 4);
> > > > +    dst += tmp;
> > > > +    src += tmp;
> > > > +    bytes -= tmp;
> > > > +
> > > > +    memcpy_fromio(dst, src, bytes);
> > > > +
> > >
> > >
> > > You could just do this!
> > >
> > >      while (bytes--)
> > >          *val++ = readb(priv->base + offset + i++);
> >
> > Do you mean that as replacement for "memcpy_fromio" or the whole
> > function code?
>
> Yes please!
>
> > The reason for using __ioread32_copy() was to improve reading
> > performance (using aligned 32 bit access where possible). I'm not sure
> > if that really matters?
>
> Just simple while loop is much readable than the previous code TBH!
>
> >
>
> > P.S.
> > Please don't yell at me in every sentence :( Makes me a bit sad :(
> Sorry!! I did not mean anything as such! :-)

All clear (I hope)! Thanks for your review!