On Mon, 31 Aug 2020, Jani Nikula <jani.nikula@xxxxxxxxx> wrote:
> On Mon, 31 Aug 2020, Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> wrote:
>> On Fri, Aug 28, 2020 at 09:19:40AM +0300, Jani Nikula wrote:
>>> The ACPI OpRegion Mailbox #5 ASLE extension may contain an EDID to be
>>> used for the embedded display. Add support for using it via the EDID
>>> override mechanism.
>>
>> Abusing the override for this feels a bit odd.
>
> It's the least intrusive way to make this work across the drm and driver
> EDID code that I could think of.
>
> BR,
> Jani.
>
>
>>
>> Also I have a vague recollection that there was perhaps some
>> linkage between the mailbox and the ACPI _DDC stuff:
>> git://github.com/vsyrjala/linux.git acpi_edid
Only looked at this now. The patch at hand is for actually overriding
the EDID from the panel, because the panel EDID is readable but bogus. I
have no idea how the ACPI _DDC stuff would work in this case. Would it
return the EDID from the panel or from mailbox #5 or something
completely different? Who knows.
Using drm_do_get_edid() would of course be doable for reading mailbox #5
directly as well, but you'd have to make that the "primary" method and
fall back to the usual drm_get_edid(). Note that this completely
prevents you from ever reading the actual panel EDID. Using
edid_override lets you get at the panel EDID too.
BR,
Jani.
>>
>>>
>>> Note that the override EDID may be later reset or changed via debugfs,
>>> as usual.
>>>
>>> Cc: Uma Shankar <uma.shankar@xxxxxxxxx>
>>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>>> ---
>>> drivers/gpu/drm/i915/display/intel_opregion.c | 46 ++++++++++++++++++-
>>> drivers/gpu/drm/i915/display/intel_opregion.h | 8 ++++
>>> 2 files changed, 53 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/display/intel_opregion.c b/drivers/gpu/drm/i915/display/intel_opregion.c
>>> index de995362f428..13485969fafa 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_opregion.c
>>> +++ b/drivers/gpu/drm/i915/display/intel_opregion.c
>>> @@ -196,6 +196,8 @@ struct opregion_asle_ext {
>>> #define ASLE_IUER_WINDOWS_BTN (1 << 1)
>>> #define ASLE_IUER_POWER_BTN (1 << 0)
>>>
>>> +#define ASLE_PHED_EDID_VALID_MASK 0x3
>>> +
>>> /* Software System Control Interrupt (SWSCI) */
>>> #define SWSCI_SCIC_INDICATOR (1 << 0)
>>> #define SWSCI_SCIC_MAIN_FUNCTION_SHIFT 1
>>> @@ -909,8 +911,10 @@ int intel_opregion_setup(struct drm_i915_private *dev_priv)
>>> opregion->asle->ardy = ASLE_ARDY_NOT_READY;
>>> }
>>>
>>> - if (mboxes & MBOX_ASLE_EXT)
>>> + if (mboxes & MBOX_ASLE_EXT) {
>>> drm_dbg(&dev_priv->drm, "ASLE extension supported\n");
>>> + opregion->asle_ext = base + OPREGION_ASLE_EXT_OFFSET;
>>> + }
>>>
>>> if (intel_load_vbt_firmware(dev_priv) == 0)
>>> goto out;
>>> @@ -1041,6 +1045,45 @@ intel_opregion_get_panel_type(struct drm_i915_private *dev_priv)
>>> return ret - 1;
>>> }
>>>
>>> +void intel_opregion_edid_override(struct intel_connector *intel_connector)
>>> +{
>>> + struct drm_connector *connector = &intel_connector->base;
>>> + struct drm_i915_private *i915 = to_i915(connector->dev);
>>> + struct intel_opregion *opregion = &i915->opregion;
>>> + const void *in_edid;
>>> + const struct edid *edid;
>>> + int len, ret;
>>> +
>>> + if (!opregion->asle_ext)
>>> + return;
>>> +
>>> + in_edid = opregion->asle_ext->bddc;
>>> +
>>> + /* Validity corresponds to number of 128-byte blocks */
>>> + len = (opregion->asle_ext->phed & ASLE_PHED_EDID_VALID_MASK) * 128;
>>> + if (!len || !memchr_inv(in_edid, 0, len))
>>> + return;
>>> +
>>> + edid = in_edid;
>>> +
>>> + /*
>>> + * FIXME: Might also check drm_edid_is_valid(edid) here but that
>>> + * requires mutable edid.
>>> + */
>>> + if (len < EDID_LENGTH * (1 + edid->extensions)) {
>>> + drm_dbg_kms(&i915->drm, "Invalid EDID in ACPI OpRegion (Mailbox #5)\n");
>>> + return;
>>> + }
>>> +
>>> + connector->override_edid = false;
>>> + ret = drm_connector_update_edid_property(connector, edid);
>>> + if (ret)
>>> + return;
>>> +
>>> + drm_dbg_kms(&i915->drm, "Using OpRegion EDID for [CONNECTOR:%d:%s]\n",
>>> + connector->base.id, connector->name);
>>> +}
>>> +
>>> void intel_opregion_register(struct drm_i915_private *i915)
>>> {
>>> struct intel_opregion *opregion = &i915->opregion;
>>> @@ -1131,6 +1174,7 @@ void intel_opregion_unregister(struct drm_i915_private *i915)
>>> opregion->acpi = NULL;
>>> opregion->swsci = NULL;
>>> opregion->asle = NULL;
>>> + opregion->asle_ext = NULL;
>>> opregion->vbt = NULL;
>>> opregion->lid_state = NULL;
>>> }
>>> diff --git a/drivers/gpu/drm/i915/display/intel_opregion.h b/drivers/gpu/drm/i915/display/intel_opregion.h
>>> index 4aa68ffbd30e..b407a0744c40 100644
>>> --- a/drivers/gpu/drm/i915/display/intel_opregion.h
>>> +++ b/drivers/gpu/drm/i915/display/intel_opregion.h
>>> @@ -29,12 +29,14 @@
>>> #include <linux/pci.h>
>>>
>>> struct drm_i915_private;
>>> +struct intel_connector;
>>> struct intel_encoder;
>>>
>>> struct opregion_header;
>>> struct opregion_acpi;
>>> struct opregion_swsci;
>>> struct opregion_asle;
>>> +struct opregion_asle_ext;
>>>
>>> struct intel_opregion {
>>> struct opregion_header *header;
>>> @@ -43,6 +45,7 @@ struct intel_opregion {
>>> u32 swsci_gbda_sub_functions;
>>> u32 swsci_sbcb_sub_functions;
>>> struct opregion_asle *asle;
>>> + struct opregion_asle_ext *asle_ext;
>>> void *rvda;
>>> void *vbt_firmware;
>>> const void *vbt;
>>> @@ -71,6 +74,7 @@ int intel_opregion_notify_encoder(struct intel_encoder *intel_encoder,
>>> int intel_opregion_notify_adapter(struct drm_i915_private *dev_priv,
>>> pci_power_t state);
>>> int intel_opregion_get_panel_type(struct drm_i915_private *dev_priv);
>>> +void intel_opregion_edid_override(struct intel_connector *connector);
>>>
>>> #else /* CONFIG_ACPI*/
>>>
>>> @@ -117,6 +121,10 @@ static inline int intel_opregion_get_panel_type(struct drm_i915_private *dev)
>>> return -ENODEV;
>>> }
>>>
>>> +void intel_opregion_edid_override(struct intel_connector *connector)
>>> +{
>>> +}
>>> +
>>> #endif /* CONFIG_ACPI */
>>>
>>> #endif
>>> --
>>> 2.20.1
>>>
>>> _______________________________________________
>>> Intel-gfx mailing list
>>> Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
>>> https://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Jani Nikula, Intel Open Source Graphics Center
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