Re: [PATCH v3 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time

[wlf]

Hi Doug,

å 2016å11æ15æ 02:17, Doug Anderson åé:
> William,
>
> On Mon, Nov 14, 2016 at 1:27 AM, William Wu <wulf@xxxxxxxxxxxxxx> wrote:
> > We found that the system crashed due to 480MHz output clock of
> > USB2 PHY was unstable after clock had been enabled by gpu module.
> >
> > Theoretically, 1 millisecond is a critical value for 480MHz
> > output clock stable time, so we try to change the delay time
> > to 1.2 millisecond to avoid this issue.
> >
> > And the commit ed907fb1d7c3 ("phy: rockchip-inno-usb2: correct
> > clk_ops callback") used prepare callbacks instead of enable
> > callbacks to support gate a clk if the operation may sleep. So
> > we can switch from delay to sleep functions.
> >
> > Signed-off-by: William Wu <wulf@xxxxxxxxxxxxxx>
> > ---
> > Changes in v3:
> > - fix kbuild test error: too few arguments to function 'usleep_range'
> >
> > Changes in v2:
> > - use usleep_range() function instead of mdelay()
> >
> >   drivers/phy/phy-rockchip-inno-usb2.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/phy/phy-rockchip-inno-usb2.c b/drivers/phy/phy-rockchip-inno-usb2.c
> > index 365e077..0e52b25 100644
> > --- a/drivers/phy/phy-rockchip-inno-usb2.c
> > +++ b/drivers/phy/phy-rockchip-inno-usb2.c
> > @@ -166,7 +166,7 @@ static int rockchip_usb2phy_clk480m_prepare(struct clk_hw *hw)
> >                          return ret;
> >
> >                  /* waitting for the clk become stable */
> > -               mdelay(1);
> > +               usleep_range(1200, 1300);
> Sight nit that you could also fix the spelling from "waitting" to "waiting".
>
> ...but that's pre-existing, so:
>
> Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Thanks! I'll add  Reviewed-by and fix the spelling issue.
>