Re: [PATCH] phy: qcom: qmp: Add debug prints for register writes

Dmitry Baryshkov
2024-07-31T12:19:28Z

On Wed, Jul 31, 2024 at 03:18:34PM GMT, Dmitry Baryshkov wrote:
> On Wed, Jul 31, 2024 at 04:28:46PM GMT, Vinod Koul wrote:
> > On 30-07-24, 15:33, Manivannan Sadhasivam wrote:
> > > These register prints are useful to validate the init sequence against the
> > > Qcom internal documentation and also to share with the Qcom hw engineers to
> > > debug issues related to PHY.
> > >
> > > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > > ---
> > > drivers/phy/qualcomm/phy-qcom-qmp-common.h | 4 ++++
> > > 1 file changed, 4 insertions(+)
> > >
> > > diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-common.h b/drivers/phy/qualcomm/phy-qcom-qmp-common.h
> > > index 799384210509..e6a6bcfcac28 100644
> > > --- a/drivers/phy/qualcomm/phy-qcom-qmp-common.h
> > > +++ b/drivers/phy/qualcomm/phy-qcom-qmp-common.h
> > > @@ -9,6 +9,7 @@
> > > struct qmp_phy_init_tbl {
> > > unsigned int offset;
> > > unsigned int val;
> > > + char *name;
> > > /*
> > > * mask of lanes for which this register is written
> > > * for cases when second lane needs different values
> > > @@ -20,6 +21,7 @@ struct qmp_phy_init_tbl {
> > > { \
> > > .offset = o, \
> > > .val = v, \
> > > + .name = #o, \
> > > .lane_mask = 0xff, \
> > > }
> > >
> > > @@ -27,6 +29,7 @@ struct qmp_phy_init_tbl {
> > > { \
> > > .offset = o, \
> > > .val = v, \
> > > + .name = #o, \
> > > .lane_mask = l, \
> > > }
> > >
> > > @@ -45,6 +48,7 @@ static inline void qmp_configure_lane(void __iomem *base,
> > > if (!(t->lane_mask & lane_mask))
> > > continue;
> > >
> > > + pr_debug("QMP PHY: Writing: %s --> 0x%02x\n", t->name, t->val);
> >
> > This lgtm, but fails to help when offset _might_ be incorrect, including
> > the offset value as well (not just the name) would be better imo...
>
> Can we please use dev_vdbg instead? Having dev_ part makes sure that we
> can not mismatch PHYs and the sequences. _vdbg is less important, but
> I don't think we want this in the log messages unless absolutely
> required.
>
> Also, could you possibly apply this to all other QMP drivers?

Please ignore the last phrase, it is used by all QMP drivers.

--
With best wishes
Dmitry