On Thu, 16 Sep 2021, Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx> wrote:
>On Thu, 16 Sep 2021, Lee Shawn C <shawn.c.lee@xxxxxxxxx> 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.
>
Create a new function in gmbus driver that allow to remove a given gmbus adapter. And DSI driver used it to unregister particular gmbus.
It looks to me more reasonable for DSI and gmbus driver. What do you think?
Best regards,
Shawn
>>
>> Cc: Jani Nikula <jani.nikula@xxxxxxxxxxxxxxx>
>> Cc: Vandita Kulkarni <vandita.kulkarni@xxxxxxxxx>
>> Cc: Cooper Chiou <cooper.chiou@xxxxxxxxx>
>> Cc: William Tseng <william.tseng@xxxxxxxxx>
>> Signed-off-by: Lee Shawn C <shawn.c.lee@xxxxxxxxx>
>> ---
>> 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
