[PATCH] ALSA: hda/i915 - avoid hung task timeout in i915 wait

Kai Vehmanen kai.vehmanen at linux.intel.com
Tue Mar 8 15:11:12 CET 2022


If kernel is built with hung task detection enabled and
CONFIG_DEFAULT_HUNG_TASK_TIMEOUT set to less than 60 seconds,
snd_hdac_i915_init() will trigger the hung task timeout in case i915 is
not available and taint the kernel.

Split the 60sec wait into a loop of smaller waits to avoid this.

Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Co-developed-by: Ramalingam C <ramalingam.c at intel.com>
Signed-off-by: Ramalingam C <ramalingam.c at intel.com>
Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>
---
 sound/hda/hdac_i915.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
index 454474ac5716..6219de739b56 100644
--- a/sound/hda/hdac_i915.c
+++ b/sound/hda/hdac_i915.c
@@ -143,7 +143,8 @@ static bool i915_gfx_present(void)
 int snd_hdac_i915_init(struct hdac_bus *bus)
 {
 	struct drm_audio_component *acomp;
-	int err;
+	unsigned long wait = 0;
+	int err, i;
 
 	if (!i915_gfx_present())
 		return -ENODEV;
@@ -159,9 +160,10 @@ int snd_hdac_i915_init(struct hdac_bus *bus)
 	if (!acomp->ops) {
 		if (!IS_ENABLED(CONFIG_MODULES) ||
 		    !request_module("i915")) {
-			/* 60s timeout */
-			wait_for_completion_timeout(&acomp->master_bind_complete,
-						    msecs_to_jiffies(60 * 1000));
+			/* max 60s timeout */
+			for (i = 0; !wait && i < 60; i++)
+				wait = wait_for_completion_timeout(&acomp->master_bind_complete,
+								   msecs_to_jiffies(1000));
 		}
 	}
 	if (!acomp->ops) {

base-commit: fd7698cf0858f8c5e659b655109cd93c2f15cdd3
-- 
2.35.1



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