Re: [PATCH] phy: renesas: rcar-gen3-usb2: Simplify ID/VBUS detection logic

[Lad, Prabhakar]

Hi Geert,

Thank you for the review.

On Tue, Mar 24, 2026 at 1:05 PM Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>
> Hi Prabhakar,
>
> On Tue, 24 Mar 2026 at 13:16, Prabhakar <prabhakar.csengg@xxxxxxxxx> wrote:
> > From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
> >
> > Read the USB2_ADPCTRL register once in rcar_gen3_check_id() and reuse
> > the value instead of performing multiple MMIO reads.
> >
> > Simplify the return logic by comparing the IDDIG and VBUSVALID bits
> > directly. This preserves the existing behaviour while improving code
> > clarity and avoiding redundant register accesses.
> >
> > Reported-by: Pavel Machek <pavel@xxxxxxxxxxxx>
> > Closes: https://lore.kernel.org/all/acJV-Xq-2uq_JFMn@xxxxxxxxxx/
> > Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
>
> Thanks for your patch!
>
> > --- a/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> > +++ b/drivers/phy/renesas/phy-rcar-gen3-usb2.c
> > @@ -314,13 +314,14 @@ static void rcar_gen3_init_from_a_peri_to_a_host(struct rcar_gen3_chan *ch)
> >  static bool rcar_gen3_check_id(struct rcar_gen3_chan *ch)
> >  {
> >         if (ch->phy_data->vblvl_ctrl) {
> > +               u32 val = readl(ch->base + USB2_ADPCTRL);
> >                 bool vbus_valid;
> >                 bool device;
> >
> > -               device = !!(readl(ch->base + USB2_ADPCTRL) & USB2_ADPCTRL_IDDIG);
> > -               vbus_valid = !!(readl(ch->base + USB2_ADPCTRL) & USB2_ADPCTRL_VBUSVALID);
> > +               device = !!(val & USB2_ADPCTRL_IDDIG);
> > +               vbus_valid = !!(val & USB2_ADPCTRL_VBUSVALID);
>
> Perhaps combine variable declarations and assignments?
> The "!!" is not needed when assigning to a bool.
>
Agreed, I will address it and send a v2.

Cheers,
Prabhakar