[PATCH] drm/gma500/cdv: Check vbt config bits when detecting lvds panels

[Hans de Goede]

Hi,

On 22-04-19 19:54, Patrik Jakobsson wrote:
> On Sun, Apr 21, 2019 at 8:46 PM Hans de Goede <hdegoede at redhat.com> wrote:
>>
>> Hi,
>>
>> On 16-04-19 13:46, Patrik Jakobsson wrote:
>>> Some machines have an lvds child device in vbt even though a panel is
>>> not attached. To make detection more reliable we now also check the lvds
>>> config bits available in the vbt.
>>>
>>> Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1665766
>>> Signed-off-by: Patrik Jakobsson <patrik.r.jakobsson at gmail.com>
>>> Cc: Hans de Goede <hdegoede at redhat.com>
>>> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
>>
>> The reporter of https://bugzilla.redhat.com/show_bug.cgi?id=1665766
>> just got back to me and he confirms that this patch fixes the
>> false-positive LVDS panel detection on his NAS, without needing
>> a DMI blacklist.
>>
>> So it looks like this patch indeed is a better fix then my initial
>> DMI blacklist approach and from my pov this patch is ready to
>> go upstream.
> 
> Thanks Hans, can I add your review tag?

Erm, then I would need to actually review it first ... done:

Reviewed-by: Hans de Goede <hdegoede at redhat.com>

Regards,

Hans


>>> ---
>>>    drivers/gpu/drm/gma500/cdv_intel_lvds.c | 3 +++
>>>    drivers/gpu/drm/gma500/intel_bios.c     | 3 +++
>>>    drivers/gpu/drm/gma500/psb_drv.h        | 1 +
>>>    3 files changed, 7 insertions(+)
>>>
>>> diff --git a/drivers/gpu/drm/gma500/cdv_intel_lvds.c b/drivers/gpu/drm/gma500/cdv_intel_lvds.c
>>> index de9531caaca0..9c8446184b17 100644
>>> --- a/drivers/gpu/drm/gma500/cdv_intel_lvds.c
>>> +++ b/drivers/gpu/drm/gma500/cdv_intel_lvds.c
>>> @@ -594,6 +594,9 @@ void cdv_intel_lvds_init(struct drm_device *dev,
>>>        int pipe;
>>>        u8 pin;
>>>
>>> +     if (!dev_priv->lvds_enabled_in_vbt)
>>> +             return;
>>> +
>>>        pin = GMBUS_PORT_PANEL;
>>>        if (!lvds_is_present_in_vbt(dev, &pin)) {
>>>                DRM_DEBUG_KMS("LVDS is not present in VBT\n");
>>> diff --git a/drivers/gpu/drm/gma500/intel_bios.c b/drivers/gpu/drm/gma500/intel_bios.c
>>> index 63bde4e86c6a..e019ea271ffc 100644
>>> --- a/drivers/gpu/drm/gma500/intel_bios.c
>>> +++ b/drivers/gpu/drm/gma500/intel_bios.c
>>> @@ -436,6 +436,9 @@ parse_driver_features(struct drm_psb_private *dev_priv,
>>>        if (driver->lvds_config == BDB_DRIVER_FEATURE_EDP)
>>>                dev_priv->edp.support = 1;
>>>
>>> +     dev_priv->lvds_enabled_in_vbt = driver->lvds_config != 0;
>>> +     DRM_DEBUG_KMS("LVDS VBT config bits: 0x%x\n", driver->lvds_config);
>>> +
>>>        /* This bit means to use 96Mhz for DPLL_A or not */
>>>        if (driver->primary_lfp_id)
>>>                dev_priv->dplla_96mhz = true;
>>> diff --git a/drivers/gpu/drm/gma500/psb_drv.h b/drivers/gpu/drm/gma500/psb_drv.h
>>> index 941b238bdcc9..bc608ddc3bd1 100644
>>> --- a/drivers/gpu/drm/gma500/psb_drv.h
>>> +++ b/drivers/gpu/drm/gma500/psb_drv.h
>>> @@ -537,6 +537,7 @@ struct drm_psb_private {
>>>        int lvds_ssc_freq;
>>>        bool is_lvds_on;
>>>        bool is_mipi_on;
>>> +     bool lvds_enabled_in_vbt;
>>>        u32 mipi_ctrl_display;
>>>
>>>        unsigned int core_freq;
>>>