[Intel-gfx] [PATCH] Revert "drm/i915: re-order if/else ladder for hpd_irq_setup"

[Lucas De Marchi]

On Fri, Nov 27, 2020 at 02:57:48PM +0000, Chris Wilson wrote:
>We now use ilk_hpd_irq_setup for all GMCH platforms that do not have
>hotplug. These are early gen3 and gen2 devices that now explode on boot
>as they try to access non-existent registers.

humn... true, my bad. But I don't think a revert is the right fix. It
would be much better if we would not be setting up the hpd setup
function at all for platforms that do not have hotplug. I think a
separate early check for I915_HAS_HOTPLUG() would be deserved.

Lucas De Marchi

>
>Fixes: 794d61a19090 ("drm/i915: re-order if/else ladder for hpd_irq_setup")
>Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>Cc: José Roberto de Souza <jose.souza at intel.com>
>Cc: Jani Nikula <jani.nikula at linux.intel.com>


>---
> drivers/gpu/drm/i915/i915_irq.c | 27 +++++++++++++++------------
> 1 file changed, 15 insertions(+), 12 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
>index dc6febc63f1c..c80eeac53952 100644
>--- a/drivers/gpu/drm/i915/i915_irq.c
>+++ b/drivers/gpu/drm/i915/i915_irq.c
>@@ -4242,18 +4242,21 @@ void intel_irq_init(struct drm_i915_private *dev_priv)
> 	 */
> 	dev_priv->hotplug.hpd_short_storm_enabled = !HAS_DP_MST(dev_priv);
>
>-	if (HAS_PCH_DG1(dev_priv))
>-		dev_priv->display.hpd_irq_setup = dg1_hpd_irq_setup;
>-	else if (INTEL_GEN(dev_priv) >= 11)
>-		dev_priv->display.hpd_irq_setup = gen11_hpd_irq_setup;
>-	else if (IS_GEN9_LP(dev_priv))
>-		dev_priv->display.hpd_irq_setup = bxt_hpd_irq_setup;
>-	else if (INTEL_PCH_TYPE(dev_priv) >= PCH_SPT)
>-		dev_priv->display.hpd_irq_setup = spt_hpd_irq_setup;
>-	else if (HAS_GMCH(dev_priv) && I915_HAS_HOTPLUG(dev_priv))
>-		dev_priv->display.hpd_irq_setup = i915_hpd_irq_setup;
>-	else
>-		dev_priv->display.hpd_irq_setup = ilk_hpd_irq_setup;
>+	if (HAS_GMCH(dev_priv)) {
>+		if (I915_HAS_HOTPLUG(dev_priv))
>+			dev_priv->display.hpd_irq_setup = i915_hpd_irq_setup;
>+	} else {
>+		if (HAS_PCH_DG1(dev_priv))
>+			dev_priv->display.hpd_irq_setup = dg1_hpd_irq_setup;
>+		else if (INTEL_GEN(dev_priv) >= 11)
>+			dev_priv->display.hpd_irq_setup = gen11_hpd_irq_setup;
>+		else if (IS_GEN9_LP(dev_priv))
>+			dev_priv->display.hpd_irq_setup = bxt_hpd_irq_setup;
>+		else if (INTEL_PCH_TYPE(dev_priv) >= PCH_SPT)
>+			dev_priv->display.hpd_irq_setup = spt_hpd_irq_setup;
>+		else
>+			dev_priv->display.hpd_irq_setup = ilk_hpd_irq_setup;
>+	}
> }
>
> /**
>-- 
>2.20.1
>