Re: [PATCH] drm/i915/bxt: WA for swapped HPD pins in A stepping

Sivakumar Thulasimani
2015-07-22T11:32:02Z

On 7/22/2015 4:39 PM, Jindal, Sonika wrote:
>
>
> On 7/22/2015 4:03 PM, Sivakumar Thulasimani wrote:
>>
>>
>> On 7/22/2015 3:37 PM, Sonika Jindal wrote:
>>> As per bspec, on BXT A0/A1, sw needs to activate DDIA HPD logic
>>> and interrupts to check the external panel connection and DDIC HPD
>>> logic for edp panel.
>>>
>>> v2: For DP, irq_port is used to determine the encoder instead of
>>> hpd_pin and removing the edp HPD logic because port A HPD is not
>>> present(Imre)
>>> v3: Rebased on top of Imre's patchset for enabling HPD on PORT A.
>>> Added hpd_pin swapping for intel_dp_init_connector, setting encoder
>>> for PORT_A as per the WA in irq_port (Imre)
>>>
>>> Signed-off-by: Sonika Jindal <sonika.jindal@intel.com>
>>> ---
>>> drivers/gpu/drm/i915/intel_ddi.c | 12 +++++++++++-
>>> drivers/gpu/drm/i915/intel_dp.c | 4 ++++
>>> drivers/gpu/drm/i915/intel_hdmi.c | 9 ++++++++-
>>> 3 files changed, 23 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c
>>> b/drivers/gpu/drm/i915/intel_ddi.c
>>> index e2c6f73..d5745e2 100644
>>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>>> @@ -3225,7 +3225,17 @@ void intel_ddi_init(struct drm_device *dev,
>>> enum port port)
>>> goto err;
>>> intel_dig_port->hpd_pulse = intel_dp_hpd_pulse;
>>> - dev_priv->hotplug.irq_port[port] = intel_dig_port;
>>> + /*
>>> + * On BXT A0/A1, sw needs to activate DDIA HPD logic and
>>> + * interrupts to check the external panel connection.
>>> + */
>>> + if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) <
>>> BXT_REVID_B0)) {
>>> + if (port == PORT_B)
>>> + dev_priv->hotplug.irq_port[PORT_A] = intel_dig_port;
>>> + else if (port == PORT_A)
>>> + dev_priv->hotplug.irq_port[PORT_C] = intel_dig_port;
>>> + } else
>>> + dev_priv->hotplug.irq_port[port] = intel_dig_port;
>>> }
>>> /* In theory we don't need the encoder->type check, but leave it
>>> just in
>>> diff --git a/drivers/gpu/drm/i915/intel_dp.c
>>> b/drivers/gpu/drm/i915/intel_dp.c
>>> index fcc64e5..71679ef 100644
>>> --- a/drivers/gpu/drm/i915/intel_dp.c
>>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>>> @@ -5785,9 +5785,13 @@ intel_dp_init_connector(struct
>>> intel_digital_port *intel_dig_port,
>>> switch (port) {
>>> case PORT_A:
>>> intel_encoder->hpd_pin = HPD_PORT_A;
>>> + if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
>>> + intel_encoder->hpd_pin = HPD_PORT_C;
>>> break;
>>> case PORT_B:
>>> intel_encoder->hpd_pin = HPD_PORT_B;
>>> + if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
>>> + intel_encoder->hpd_pin = HPD_PORT_A;
>>> break;
>>> case PORT_C:
>>> intel_encoder->hpd_pin = HPD_PORT_C;
>>> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c
>>> b/drivers/gpu/drm/i915/intel_hdmi.c
>>> index 70bad5b..94fa716 100644
>>> --- a/drivers/gpu/drm/i915/intel_hdmi.c
>>> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
>>> @@ -1973,7 +1973,14 @@ void intel_hdmi_init_connector(struct
>>> intel_digital_port *intel_dig_port,
>>> intel_hdmi->ddc_bus = GMBUS_PIN_1_BXT;
>>> else
>>> intel_hdmi->ddc_bus = GMBUS_PIN_DPB;
>>> - intel_encoder->hpd_pin = HPD_PORT_B;
>>> + /*
>>> + * On BXT A0/A1, sw needs to activate DDIA HPD logic and
>>> + * interrupts to check the external panel connection.
>>> + */
>>> + if (IS_BROXTON(dev_priv) && (INTEL_REVID(dev) < BXT_REVID_B0))
>>> + intel_encoder->hpd_pin = HPD_PORT_A;
>>> + else
>>> + intel_encoder->hpd_pin = HPD_PORT_B;
>>> break;
>>> case PORT_C:
>>> if (IS_BROXTON(dev_priv))
>> bxt_hpd_irq_setup is not touched here without this being updated i dont
>> think HPD can be enabled.
> Now, we swap the hpd_pin, which is being used to enable HPD in
> bxt_hpd_irq_setup.
>
yes, but the hpd_pin which is updated to HPD_PORT_A when enters
bxt_hpd_setup_irq we are enabling
only HPD B & C. so it will not enable HPDA. unless i am missing some
patch i am not seeing code to
enable HPD A with latest nightly code.

> Regards,
> Sonika
>>

--
regards,
Sivakumar