Re: [PATCH RSEND] drm/bridge: analogix_dp: use devm_phy_optional_get() for the DP PHY

From: Jun Yan

Date: Thu Sep 24 2026 - 07:20:06 EST


> On 9/24/2026 11:24 AM, Damon Ding wrote:
> > Hi Jun,
> >
> > On 9/24/2026 10:04 AM, Jun Yan wrote:
> >> The DP PHY is optional: the Rockchip RK3399 eDP controller (used as the
> >> internal eDP port) has no separate PHY device and relies on its built-in
> >> PHY, which is programmed directly through the GRF registers, so its DT
> >> node carries no "phys"/"phy-names" property.
> >>
> >> Requesting the PHY with devm_phy_get() therefore returns -ENODEV (or
> >> -ENOSYS when CONFIG_GENERIC_PHY is disabled) and the driver logs a
> >> misleading "no DP phy configured" error at probe time before falling back
> >> to a NULL phy.
> >>
> >> Use devm_phy_optional_get() instead, which returns NULL when the PHY is
> >> absent and otherwise behaves identically, and drop the manual -ENODEV/
> >> -ENOSYS handling. This also removes the spurious error message.
> >>
> >> Assisted-by: Claude:deepseek-v4-flash
> >> Signed-off-by: Jun Yan <jerrysteve1101@xxxxxxxxx>
> >> ---
> >>   .../gpu/drm/bridge/analogix/analogix_dp_core.c | 18 +++---------------
> >>   1 file changed, 3 insertions(+), 15 deletions(-)
> >>
> >> diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/
> >> drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> >> index 18e76d1e78e1..28eb668d3e3f 100644
> >> --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> >> +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> >> @@ -1427,21 +1427,9 @@ analogix_dp_probe(struct device *dev, struct
> >> analogix_dp_plat_data *plat_data)
> >>       if (ret)
> >>           return ERR_PTR(ret);
> >> -    dp->phy = devm_phy_get(dp->dev, "dp");
> >> -    if (IS_ERR(dp->phy)) {
> >> -        dev_err(dp->dev, "no DP phy configured\n");
> >> -        ret = PTR_ERR(dp->phy);
> >> -        if (ret) {
> >> -            /*
> >> -             * phy itself is not enabled, so we can move forward
> >> -             * assigning NULL to phy pointer.
> >> -             */
> >> -            if (ret == -ENOSYS || ret == -ENODEV)
> >> -                dp->phy = NULL;
> >> -            else
> >> -                return ERR_PTR(ret);
> >> -        }
> >> -    }
> >
> > It should be better to add some comments here:
> >
> > /*
> >  * Exynos5/RK3288/RK3399 use Analogix DP controller built-in PHY,
> >  * no separate PHY configuration is needed.
> >  */
>
> Well, I think it should be fixed to:
>
> /*
> * RK3288/RK3399 use Analogix DP controller built-in PHY,
> * no extra PHY configuration is required.
> */
>
> The Exynos5xxx case may be more complex.
>

Thanks for the review. I will add the comments in the patch and send v2 soon.

> >
> >> +    dp->phy = devm_phy_optional_get(dp->dev, "dp");
> >> +    if (IS_ERR(dp->phy))
> >> +        return ERR_CAST(dp->phy);
> >>       dp->clock = devm_clk_get(&pdev->dev, "dp");
> >>       if (IS_ERR(dp->clock)) {
> >
> > With the comment added:
> > Reviewed-by: Damon Ding <damon.ding@xxxxxxxxxxxxxx>
> >
> > Best regards,
> > Damon
> >