Re: [PATCH v3 1/3] phy: amlogic: phy-meson-gxl-usb2: fix shared reset controller use

[Amjad Ouled-Ameur]

Hi Philipp,

Thank you for the review.

On 22/11/2021 10:03, Philipp Zabel wrote:
> Hi Amjad,
>
> On Fri, 2021-11-12 at 17:28 +0100, Amjad Ouled-Ameur wrote:
> > Use reset_control_rearm() call if an error occurs in case
> > phy_meson_gxl_usb2_init() fails after reset() has been called ; or in case
> > phy_meson_gxl_usb2_exit() is called i.e the resource is no longer used
> > and the reset line may be triggered again by other devices.
> >
> > reset_control_rearm() keeps use of triggered_count sane in the reset
> > framework. Therefore, use of reset_control_reset() on shared reset line
> > should be balanced with reset_control_rearm().
> >
> > Signed-off-by: Amjad Ouled-Ameur <aouledameur@xxxxxxxxxxxx>
> > Reported-by: Jerome Brunet <jbrunet@xxxxxxxxxxxx>
> > ---
> >   drivers/phy/amlogic/phy-meson-gxl-usb2.c | 5 ++++-
> >   1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/phy/amlogic/phy-meson-gxl-usb2.c b/drivers/phy/amlogic/phy-meson-gxl-usb2.c
> > index 2b3c0d730f20..9a9c769ecabc 100644
> > --- a/drivers/phy/amlogic/phy-meson-gxl-usb2.c
> > +++ b/drivers/phy/amlogic/phy-meson-gxl-usb2.c
> > @@ -110,8 +110,10 @@ static int phy_meson_gxl_usb2_init(struct phy *phy)
> >   	int ret;
> >
> >   	ret = reset_control_reset(priv->reset);
> > -	if (ret)
> > +	if (ret) {
> > +		reset_control_rearm(priv->reset);
> I don't understand this. If reset_control_reset() returns an error for a
> shared reset, it should have either
> - returned before incrementing triggered_count, or
> - incremented triggered_count, got a failed reset op, decremented
>    triggered_count again
>
> In both cases there should be no need to rearm.
I have checked this out and I agree with you, will remove this in next 
version.

Thank you for spotting this.


Regards,

Amjad

> regards
> Philipp