[Intel-gfx] [PATCH] drm/i915: Reset the interrupt mask on disabling interrupts

[Ville Syrjälä]

On Thu, Oct 22, 2020 at 08:16:37AM +0100, Chris Wilson wrote:
> As we disable the interrupt during suspend, also reset the irq_mask to
> short-circuit subsystems that later try to turn off their interrupt
> source.
> 
> <4>[  101.816730] i915 0000:00:02.0: drm_WARN_ON(!intel_irqs_enabled(dev_priv))
> <4>[  101.816853] WARNING: CPU: 3 PID: 4241 at drivers/gpu/drm/i915/i915_irq.c:343 ilk_update_display_irq+0xb3/0x130 [i915]

Doh. Lack of irq symmetry in suspend vs. resume strikes again :(

> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/i915_irq.c | 25 ++++++++++---------------
>  1 file changed, 10 insertions(+), 15 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 09221ca1ffb2..cbb71fc73313 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -337,17 +337,14 @@ void ilk_update_display_irq(struct drm_i915_private *dev_priv,
>  	u32 new_val;
>  
>  	lockdep_assert_held(&dev_priv->irq_lock);
> -
>  	drm_WARN_ON(&dev_priv->drm, enabled_irq_mask & ~interrupt_mask);
>  
> -	if (drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv)))
> -		return;
> -
>  	new_val = dev_priv->irq_mask;
>  	new_val &= ~interrupt_mask;
>  	new_val |= (~enabled_irq_mask & interrupt_mask);
>  
> -	if (new_val != dev_priv->irq_mask) {
> +	if (new_val != dev_priv->irq_mask &&
> +	    !drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv))) {
>  		dev_priv->irq_mask = new_val;
>  		I915_WRITE(DEIMR, dev_priv->irq_mask);
>  		POSTING_READ(DEIMR);
> @@ -368,19 +365,16 @@ static void bdw_update_port_irq(struct drm_i915_private *dev_priv,
>  	u32 old_val;
>  
>  	lockdep_assert_held(&dev_priv->irq_lock);
> -
>  	drm_WARN_ON(&dev_priv->drm, enabled_irq_mask & ~interrupt_mask);
>  
> -	if (drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv)))
> -		return;
> -
>  	old_val = I915_READ(GEN8_DE_PORT_IMR);
>  
>  	new_val = old_val;
>  	new_val &= ~interrupt_mask;
>  	new_val |= (~enabled_irq_mask & interrupt_mask);
>  
> -	if (new_val != old_val) {
> +	if (new_val != old_val &&
> +	    !drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv))) {
>  		I915_WRITE(GEN8_DE_PORT_IMR, new_val);
>  		POSTING_READ(GEN8_DE_PORT_IMR);
>  	}
> @@ -401,17 +395,14 @@ void bdw_update_pipe_irq(struct drm_i915_private *dev_priv,
>  	u32 new_val;
>  
>  	lockdep_assert_held(&dev_priv->irq_lock);
> -
>  	drm_WARN_ON(&dev_priv->drm, enabled_irq_mask & ~interrupt_mask);
>  
> -	if (drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv)))
> -		return;
> -
>  	new_val = dev_priv->de_irq_mask[pipe];
>  	new_val &= ~interrupt_mask;
>  	new_val |= (~enabled_irq_mask & interrupt_mask);
>  
> -	if (new_val != dev_priv->de_irq_mask[pipe]) {
> +	if (new_val != dev_priv->de_irq_mask[pipe] &&
> +	    !drm_WARN_ON(&dev_priv->drm, !intel_irqs_enabled(dev_priv))) {
>  		dev_priv->de_irq_mask[pipe] = new_val;
>  		I915_WRITE(GEN8_DE_PIPE_IMR(pipe), dev_priv->de_irq_mask[pipe]);
>  		POSTING_READ(GEN8_DE_PIPE_IMR(pipe));

Not resetting de_irq_mask[] anywhere? Hmm. we seem to be lacking a
gen8_de_irq_reset()...

> @@ -2951,6 +2942,8 @@ static void ilk_irq_reset(struct drm_i915_private *dev_priv)
>  	struct intel_uncore *uncore = &dev_priv->uncore;
>  
>  	GEN3_IRQ_RESET(uncore, DE);
> +	dev_priv->irq_mask = ~0u;
> +
>  	if (IS_GEN(dev_priv, 7))
>  		intel_uncore_write(uncore, GEN7_ERR_INT, 0xffffffff);
>  
> @@ -3864,6 +3857,7 @@ static void i915_irq_reset(struct drm_i915_private *dev_priv)
>  	i9xx_pipestat_irq_reset(dev_priv);
>  
>  	GEN3_IRQ_RESET(uncore, GEN2_);
> +	dev_priv->irq_mask = ~0u;
>  }
>  
>  static void i915_irq_postinstall(struct drm_i915_private *dev_priv)
> @@ -3970,6 +3964,7 @@ static void i965_irq_reset(struct drm_i915_private *dev_priv)
>  	i9xx_pipestat_irq_reset(dev_priv);
>  
>  	GEN3_IRQ_RESET(uncore, GEN2_);
> +	dev_priv->irq_mask = ~0u;
>  }

Missing gen2?

>  
>  static void i965_irq_postinstall(struct drm_i915_private *dev_priv)
> -- 
> 2.20.1

-- 
Ville Syrjälä
Intel