Re: [EXT] Re: [PATCH/RFC v2 net-next] ravb: unmap descriptors when freeing rings

[Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>]

On 01/12/2017 07:55 PM, Lino Sanfilippo wrote:

> > > > > > +
> > > > > > +    for (; priv->cur_tx[q] - priv->dirty_tx[q] > 0; priv->dirty_tx[q]++) {
> > >
> > > BTW: How can this work correctly when cur_tx wraps and dirty_tx is greater?
> >
> >    {cur|dirty}_tx never wrap.
>
> Both values are 32 bit and AFAICS they are only incremented (and never reset or
> decremented).

   Yeah, sorry, O thought you mean the TX ring size wrapping.

> So what prevents them from wrapping every 2^32 processed tx descriptors? Am I
> missing
> something?

   The math should still work all right IIUC.

> Regards,
> Lino

MBR, Sergei