Re: [PATCH v3 1/2] phy: qcom: edp: Add eDP/DP mode switch support

[Yongxing Mou]

On 4/21/2026 2:32 AM, Dmitry Baryshkov wrote:
> On Mon, Apr 20, 2026 at 08:47:09PM +0800, Yongxing Mou wrote:
> > On 3/20/2026 2:36 PM, Dmitry Baryshkov wrote:
> > > On Mon, Mar 02, 2026 at 04:28:29PM +0800, Yongxing Mou wrote:
> > > > The eDP PHY supports both eDP&DP modes, each requires a different table.
> > > > The current driver doesn't fully support every combo PHY mode and use
> > > > either the eDP or DP table when enable the platform. In addition, some
> > > > platforms mismatch between the mode and the table where DP mode uses
> > > > the eDP table or eDP mode use the DP table.
> > > >
> > > > Clean up and correct the tables for currently supported platforms based on
> > > > the HPG specification.
> > > >
> > > > Here lists the tables can be reused across current platforms.
> > > > DP mode：
> > > > 	-sa8775p/sc7280/sc8280xp/x1e80100
> > > > 	-glymur
> > > > eDP mode(low vdiff):
> > >
> > > Separate question: should we extend phy_configure_dp_opts with the
> > > low/high vdiff? Is there a point in providing the ability to toggle
> > > between low vdiff and high vdiff?
> > Emm ,i haven't found any platform using high vdiff so far, and I'm not clear
> > in which cases switching between low and high vdiff would be needed.
>
>  From my (maybe incorrect) understanding of eDP B.3, the high vs low
> vdiff selection should be based on the cable length.
Thanks for the explanation. Maybe we can add this when we really need it.
> > > > 	-glymur/sa8775p/sc8280xp/x1e80100
> > > > 	-sc7280
> > >
> > > I understand your wish to perform all the changes in a single patch, but
> > > there is one problem with that. Consider this patch regresses one of the
> > > platforms (I'm looking at Kodiak and SC8180X as they get the biggest set
> > > of changes). It would be almost impossible to separate, which particular
> > > change caused the regression. I'd suggest splitting this patch into a
> > > set of more atomic changes. E.g. the AUX_CFG8 is definitely a separate
> > > change. Writing swing / pre_emph tables on Kodiak and SC8180X is a
> > > separate change (or two). Switching each of the platforms to the
> > > corrected set of tables ideally also should come as a separate change,
> > > so that in case of a regression the issue would be easier to identify.
> > Thank for point this, will separate the change.
> > I mostly overlooked SC8180X here, since I assumed it shares the same PHY as
> > SC7280. However, they are using different PHY sub‑versions. Will add proper
> > support for it in the next version.
>
> Thanks!
Emm, one more question.. Based on Konard's comments, should I split this 
patch, and send a new revision, or  post a new SC8180X patch on top of 
these two existing patches?
> > > > Cc: stable@xxxxxxxxxxxxxxx
> > > > Fixes: f199223cb490 ("phy: qcom: Introduce new eDP PHY driver")
> > > > Signed-off-by: Yongxing Mou <yongxing.mou@xxxxxxxxxxxxxxxx>
> > > > ---
> > > >    drivers/phy/qualcomm/phy-qcom-edp.c | 90 ++++++++++++++++++++++---------------
> > > >    1 file changed, 53 insertions(+), 37 deletions(-)