On Thu, 16 Sep 2021, Lee Shawn C <[email protected]> wrote: > Gmbus driver would setup all Intel i2c GMBuses. But DDC bus > may configured as gpio and reserved for MIPI driver to control > panel power on/off sequence. > > Using i2c tool to communicate to peripherals via i2c interface > reversed for gmbus(DDC). There will be some high/low pulse > appear on DDC SCL and SDA (might be host sent out i2c slave > address). MIPI panel would be impacted due to unexpected signal > then caused abnormal display or shut down issue.
Just a quick reply: So I don't know off the bat what the right solution is, but it's very obvious to me that we absolute can't go deleting gmbus adapters from DSI code. BR, Jani. > > Cc: Jani Nikula <[email protected]> > Cc: Vandita Kulkarni <[email protected]> > Cc: Cooper Chiou <[email protected]> > Cc: William Tseng <[email protected]> > Signed-off-by: Lee Shawn C <[email protected]> > --- > drivers/gpu/drm/i915/display/icl_dsi.c | 14 ++++++++++++++ > 1 file changed, 14 insertions(+) > > diff --git a/drivers/gpu/drm/i915/display/icl_dsi.c > b/drivers/gpu/drm/i915/display/icl_dsi.c > index 060bc8fb0d30..d2504e291fcb 100644 > --- a/drivers/gpu/drm/i915/display/icl_dsi.c > +++ b/drivers/gpu/drm/i915/display/icl_dsi.c > @@ -1999,6 +1999,7 @@ void icl_dsi_init(struct drm_i915_private *dev_priv) > struct intel_connector *intel_connector; > struct drm_connector *connector; > struct drm_display_mode *fixed_mode; > + struct intel_gmbus *bus; > enum port port; > > if (!intel_bios_is_dsi_present(dev_priv, &port)) > @@ -2092,6 +2093,19 @@ void icl_dsi_init(struct drm_i915_private *dev_priv) > icl_dphy_param_init(intel_dsi); > > icl_dsi_add_properties(intel_connector); > + > + /* > + * DDC bus may configured as gpio and reserved for MIPI driver > + * to control panel power on/off sequence. so, unregister gmbus > + * if MIPI was LFP display. > + */ > + bus = &dev_priv->gmbus[GMBUS_PIN_1_BXT]; > + i2c_del_adapter(&bus->adapter); > + > + if (dev_priv->vbt.dsi.config->dual_link) { > + bus = &dev_priv->gmbus[GMBUS_PIN_2_BXT]; > + i2c_del_adapter(&bus->adapter); > + } > return; > > err: -- Jani Nikula, Intel Open Source Graphics Center
