Re: [PATCH] drm/i915: Fixup hpd irq register setup ordering

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Sun,  9 Dec 2012 20:42:01 +0100
Daniel Vetter <daniel.vetter@ffwll.ch> wrote:

> For GMCH platforms we set up the hpd irq registers in the irq
> postinstall hook. But since we only enable the irq sources we actually
> need in PORT_HOTPLUG_EN/STATUS, taking dev_priv->hotplug_supported_mask
> into account, no hpd interrupt sources is enabled since
> 
> commit 52d7ecedac3f96fb562cb482c139015372728638
> Author: Daniel Vetter <daniel.vetter@ffwll.ch>
> Date:   Sat Dec 1 21:03:22 2012 +0100
> 
>     drm/i915: reorder setup sequence to have irqs for output setup
> 
> Wrongly set-up interrupts also lead broken hw-based load-detection on
> at least GM45, resulting in ghost VGA/TV-out outputs.

..."can lead to broken"... or "also leads to" ?

> +
> +void intel_hpd_init(struct drm_device *dev)
> +{
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +	if (dev_priv->display.hpd_irq_setup)
> +		dev_priv->display.hpd_irq_setup(dev);
> +
> +	/*
> +	 * Some ports require correctly set-up hpd registers for detection to
> +	 * work properly, e.g. VGA on gm45. Hence we can only set up the initial
> +	 * fbdev config after hpd irqs are fully enabled. Now we should scan for
> +	 * the initial config only once hotplug handling is enabled, but due to
> +	 * screwed-up locking around kms/fbdev init we can't protect the fdbev
> +	 * initial config scanning against hotplug events. Hence do this first
> +	 * and ignore the tiny window where we will loose hotplug notifactions.
> +	 */
> +	intel_fbdev_initial_config(dev);
> +
> +	/* Only enable hotplug handling once the fbdev is fully set up. */
> +	dev_priv->enable_hotplug_processing = true;
> +
> +	drm_kms_helper_poll_init(dev);
> +}

I'd rather see these calls in load_modeset_init().  Having
fbdev_initial_config here at least is confusing, and since poll_init
depends on it...

With those two nits:

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center