EDID reading failed when using DVI-to-VGA connector in valleyview(device id: 0x0f31)

[Jani Nikula]

On Thu, 29 Sep 2016, 杨波 <yangbo at deepin.com> wrote:
> Hi, everyone:
>     Reading EDID failed when using DVI-to-VGA connector in valleyview(device 
> id: 0x0f31). 
> It is not G4X device，but still need to probe digital port. 

I don't think the patch is acceptable, at least not without a proper
explanation and debugging of the problem. Please file a bug at [1], add
drm.debug=14 module parameter and attach dmesg on the bug.

BR,
Jani.

[1] https://bugs.freedesktop.org/enter_bug.cgi?product=DRI&component=DRM/Intel



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> From e2dbb517239b5f03da7578e9e350013f8e9c2b3a Mon Sep 17 00:00:00 2001
> From: Yang Bo <yangbo at deepin.com>
> Date: Thu, 29 Sep 2016 14:48:32 +0800
> Subject: [PATCH] EDID reading failure in 0x0f31
>
> EDID reading failure is observed in valleyview(device id: 0x0f31)
> when using DVI-to-VGA connector.
>
> Signed-off-by: Yang Bo <yangbo at deepin.com>
> ---
>  drivers/gpu/drm/i915/intel_crt.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_crt.c 
> b/drivers/gpu/drm/i915/intel_crt.c
> index 827b6ef..83662fa 100644
> --- a/drivers/gpu/drm/i915/intel_crt.c
> +++ b/drivers/gpu/drm/i915/intel_crt.c
> @@ -715,7 +715,7 @@ static int intel_crt_get_modes(struct drm_connector 
> *connector)
>  
>       i2c = intel_gmbus_get_adapter(dev_priv, dev_priv->vbt.crt_ddc_pin);
>       ret = intel_crt_ddc_get_modes(connector, i2c);
> -     if (ret || !IS_G4X(dev))
> +     if (ret || !(IS_G4X(dev) || (dev->pdev->device == 0x0f31)))
>               goto out;
>  
>       /* Try to probe digital port for output in DVI-I -> VGA mode. */

-- 
Jani Nikula, Intel Open Source Technology Center