On Sun, 11 Jan 2026, TrainedPro <[email protected]> wrote: > The Parade PS175 LSPCON chip often requires up to 800ms to settle after a > mode change, particularly during resume. > > Although the Intel driver (intel_lspcon.c) is aware of this 800ms > requirement, it calls the shared helper `drm_lspcon_set_mode()`, which > currently hardcodes a 200ms timeout. This specific implementation forces a > 200ms limit, effectively overriding the driver's knowledge and causing the > mode change to time out prematurely, which results in a black screen (never > waking up). > > This patch increases the hardcoded timeout in the helper from 200ms to > 1000ms. Since the function polls for the status bit, this change does not > penalize faster chips but ensures correct operation for slower ones like the > PS175. > > Signed-off-by: TrainedPro <[email protected]>
Is there an existing gitlab issue with dmesg logs about the issue? See [1] for how to report one. BR, Jani. [1] https://drm.pages.freedesktop.org/intel-docs/how-to-file-i915-bugs.html > --- > drivers/gpu/drm/display/drm_dp_dual_mode_helper.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c > b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c > index 719da3610310f..fda3cb4966adf 100644 > --- a/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c > +++ b/drivers/gpu/drm/display/drm_dp_dual_mode_helper.c > @@ -495,7 +495,7 @@ int drm_lspcon_set_mode(const struct drm_device *dev, > struct i2c_adapter *adapte > { > u8 data = 0; > int ret; > - int time_out = 200; > + int time_out = 1000; > enum drm_lspcon_mode current_mode; > > if (mode == DRM_LSPCON_MODE_PCON) -- Jani Nikula, Intel
