Re: [PATCH v4 0/9] drm/msm/dp: Drop the HPD state machine

[Dmitry Baryshkov]

On Mon, Mar 09, 2026 at 01:45:34PM +0100, Konrad Dybcio wrote:
> On 3/5/26 3:30 PM, Dmitry Baryshkov wrote:
> > Currently, all HPD interrupt handling must go through the HPD state
> > machine.
> > 
> > This has caused many issues where the DRM framework assumes that DP is
> > in one state while the state machine is stuck in another state.
> > 
> > As discussed here [1], this series:
> > 
> > - Removes the state machine
> > - Moves link training to atomic_enable()
> > - Changes the detect() behavior to return true if a display is physically
> >   plugged in (as opposed to if the DP link is ready).
> > - Remove event queue and move internal HPD handling to hpd_notify()
> > 
> > Note: eDP is mostly untested. This will be sorted out before the next
> > iteration, but it will not affect the series in a major way.
> > 
> > Note 2: there is an issue with the DP connectors using GPIO for HPD
> > (rather than using the nativate DP HPD pin), the DP will not detect a
> > display if it is plugged in before the board is booted. This is not an
> > issue of this series and it will be handled by a separate series to be
> > posted today or tomorrow.
> > 
> > [1] https://patchwork.freedesktop.org/patch/656312/?series=142010&rev=2#comment_1201738
> > 
> > ---
> > Changes in v4:
> > - Fixed PM runtime handling
> > - Fixed several cases where the HPD machine would loose its state
> > - Fixed the case where detection was ignoring the plugging in display.
> 
> - forgot to run b4 trailers -u

Mea culpa!

> 
> (no worries though)
> 
> Konrad

-- 
With best wishes
Dmitry