Re: [Intel-gfx] [PATCH] drm/i915: Remove unused IRQ chip data of HDMI LPE audio

From: "Ville Syrjälä" <ville.syrjala@linux.intel.com>
To: "Augustine.Chen" <augustine.chen@intel.com>
Cc: intel-gfx@lists.freedesktop.org, alsa-devel@alsa-project.org,
	jerome.anand@intel.com, pierre-louis.bossart@intel.com,
	tiwai@suse.de, Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
	Jiang Liu <jiang.liu@linux.intel.com>,
	Juergen Gross <jgross@suse.com>,
	Dou Liyang <douly.fnst@cn.fujitsu.com>,
	linux-kernel@vger.kernel.org
Subject: Re: [Intel-gfx] [PATCH] drm/i915: Remove unused IRQ chip data of HDMI LPE audio
Date: Fri, 8 Dec 2017 13:44:04 +0200	[thread overview]
Message-ID: <20171208114404.GN10981@intel.com> (raw)
In-Reply-To: <20171208093323.2212-1-augustine.chen@intel.com>

On Fri, Dec 08, 2017 at 05:33:23PM +0800, Augustine.Chen wrote:
> The chip data of HDMI LPE audio is set to drm_i915_private which is not
> consistent with the expectation by x86 APIC driver.

Hmm. Why is the apic code looking at data for an irq chip it
hasn't created?

Do we need something like
- dev_priv->lpe_audio.irq = irq_alloc_desc(0);
+ dev_priv->lpe_audio.irq = irq_alloc_desc(-1);
?

That *looks* more correct to me based on a cursory glance at the x86
code, but I didn't trawl very deeply.

> In the case of not
> enabling CONFIG_CPUMASK_OFFSTACK, this would cause kernel panic while doing
> CPU hotplug. Since the dependency of IRQ chip data was removed from HDMI
> LPE audio by Commit 9bd9590997b92fbd79fd028f704f6c584b4439d7 ("drm/i915:
> Stop pretending to mask/unmask LPE audio interrupts"), remove the
> code of setting IRQ chip data to resolve this issue.
> 
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=103731
> Cc: Pierre-Louis Bossart <pierre-louis.bossart@intel.com>
> Cc: Jerome Anand <jerome.anand@intel.com>
> Cc: Takashi Iwai <tiwai@suse.de>
> Signed-off-by: Augustine.Chen <augustine.chen@intel.com>
> ---
>  drivers/gpu/drm/i915/intel_lpe_audio.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_lpe_audio.c b/drivers/gpu/drm/i915/intel_lpe_audio.c
> index 3bf6528..56176f9 100644
> --- a/drivers/gpu/drm/i915/intel_lpe_audio.c
> +++ b/drivers/gpu/drm/i915/intel_lpe_audio.c
> @@ -176,7 +176,7 @@ static int lpe_audio_irq_init(struct drm_i915_private *dev_priv)
>  				handle_simple_irq,
>  				"hdmi_lpe_audio_irq_handler");
>  
> -	return irq_set_chip_data(irq, dev_priv);
> +	return 0;
>  }
>  
>  static bool lpe_audio_detect(struct drm_i915_private *dev_priv)
> -- 
> 1.9.1
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Ville Syrjälä
Intel OTC