Re: [PATCH 5/6] phy: qcom-qmp-combo: fix drm bridge registration

[Dmitry Baryshkov]

On Sat, 17 Feb 2024 at 17:03, Johan Hovold <johan+linaro@xxxxxxxxxx> wrote:
>
> Due to a long-standing issue in driver core, drivers may not probe defer
> after having registered child devices to avoid triggering a probe
> deferral loop (see fbc35b45f9f6 ("Add documentation on meaning of
> -EPROBE_DEFER")).
>
> This could potentially also trigger a bug in the DRM bridge
> implementation which does not expect bridges to go away even if device
> links may avoid triggering this (when enabled).
>
> Move registration of the DRM aux bridge to after looking up clocks and
> other resources.
>
> Note that PHY creation can in theory also trigger a probe deferral when
> a 'phy' supply is used. This does not seem to affect the QMP PHY driver
> but the PHY subsystem should be reworked to address this (i.e. by
> separating initialisation and registration of the PHY).
>
> Fixes: 35921910bbd0 ("phy: qcom: qmp-combo: switch to DRM_AUX_BRIDGE")
> Fixes: 1904c3f578dc ("phy: qcom-qmp-combo: Introduce drm_bridge")
> Cc: stable@xxxxxxxxxxxxxxx      # 6.5
> Cc: Bjorn Andersson <quic_bjorande@xxxxxxxxxxx>
> Cc: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
> Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>


-- 
With best wishes
Dmitry