Re: [PATCH linux-next 1/1] phy: Sparx5 Eth SerDes: Use direct register operations

[Steen Hegelund]

Hi Andrew,

On Mon, 2021-03-29 at 20:55 +0200, Andrew Lunn wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> On Mon, Mar 29, 2021 at 10:14:38AM +0200, Steen Hegelund wrote:
> > Use direct register operations instead of a table of register
> > information to lower the stack usage.
> > 
> > Signed-off-by: Steen Hegelund <steen.hegelund@xxxxxxxxxxxxx>
> > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > ---
> >  drivers/phy/microchip/sparx5_serdes.c | 1869 +++++++++++++------------
> >  1 file changed, 951 insertions(+), 918 deletions(-)
> > 
> > diff --git a/drivers/phy/microchip/sparx5_serdes.c b/drivers/phy/microchip/sparx5_serdes.c
> > index 06bcf0c166cf..43de68a62c2f 100644
> > --- a/drivers/phy/microchip/sparx5_serdes.c
> > +++ b/drivers/phy/microchip/sparx5_serdes.c
> > @@ -343,12 +343,6 @@ struct sparx5_sd10g28_params {
> >       u8 fx_100;
> >  };
> > 
> > -struct sparx5_serdes_regval {
> > -     u32 value;
> > -     u32 mask;
> > -     void __iomem *addr;
> > -};
> > -
> >  static struct sparx5_sd25g28_media_preset media_presets_25g[] = {
> >       { /* ETH_MEDIA_DEFAULT */
> >               .cfg_en_adv               = 0,
> > @@ -945,431 +939,411 @@ static void sparx5_sd25g28_reset(void __iomem *regs[],
> >       }
> >  }
> > 
> > -static int sparx5_sd25g28_apply_params(struct device *dev,
> > -                                    void __iomem *regs[],
> > -                                    struct sparx5_sd25g28_params *params,
> > -                                    u32 sd_index)
> > +static int sparx5_sd25g28_apply_params(struct sparx5_serdes_macro *macro,
> > +                                    struct sparx5_sd25g28_params *params)
> >  {
> > -     struct sparx5_serdes_regval item[] = {
> 
> Could you just add const here, and then it is no longer on the stack?
> 
>    Andrew

No it still counts against the stack even as a const structure.

BR
Steen