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From:   gregkh@linuxfoundation.org
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Takashi Iwai <tiwai@suse.de>,
        Abhishek Sahu <abhsahu@nvidia.com>
Subject: [PATCH 4.9 25/78] ALSA: hda/hdmi: Cancel pending works before suspend
Date:   Mon, 15 Mar 2021 14:51:48 +0100
Message-Id: <20210315135212.885665069@linuxfoundation.org>
In-Reply-To: <20210315135212.060847074@linuxfoundation.org>
References: <20210315135212.060847074@linuxfoundation.org>
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Takashi Iwai <tiwai@suse.de>

commit eea46a0879bcca23e15071f9968c0f6e6596e470 upstream.

The per_pin->work might be still floating at the suspend, and this may
hit the access to the hardware at an unexpected timing.  Cancel the
work properly at the suspend callback for avoiding the buggy access.

Note that the bug doesn't trigger easily in the recent kernels since
the work is queued only when the repoll count is set, and usually it's
only at the resume callback, but it's still possible to hit in
theory.

BugLink: https://bugzilla.suse.com/show_bug.cgi?id=1182377
Reported-and-tested-by: Abhishek Sahu <abhsahu@nvidia.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210310112809.9215-4-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/pci/hda/patch_hdmi.c |   13 +++++++++++++
 1 file changed, 13 insertions(+)

--- a/sound/pci/hda/patch_hdmi.c
+++ b/sound/pci/hda/patch_hdmi.c
@@ -2156,6 +2156,18 @@ static void generic_hdmi_free(struct hda
 }
 
 #ifdef CONFIG_PM
+static int generic_hdmi_suspend(struct hda_codec *codec)
+{
+	struct hdmi_spec *spec = codec->spec;
+	int pin_idx;
+
+	for (pin_idx = 0; pin_idx < spec->num_pins; pin_idx++) {
+		struct hdmi_spec_per_pin *per_pin = get_pin(spec, pin_idx);
+		cancel_delayed_work_sync(&per_pin->work);
+	}
+	return 0;
+}
+
 static int generic_hdmi_resume(struct hda_codec *codec)
 {
 	struct hdmi_spec *spec = codec->spec;
@@ -2179,6 +2191,7 @@ static const struct hda_codec_ops generi
 	.build_controls		= generic_hdmi_build_controls,
 	.unsol_event		= hdmi_unsol_event,
 #ifdef CONFIG_PM
+	.suspend		= generic_hdmi_suspend,
 	.resume			= generic_hdmi_resume,
 #endif
 };