ENGR00172374-7 Sound: Asoc: fix the snd_soc_resume resume crash

[  330.922320] [<800417e0>] (__bug+0x1c/0x24) from [<8007b4dc>] (__queue_work+0x24c/0x3f0)
[  330.930333] [<8007b4dc>] (__queue_work+0x24c/0x3f0) from [<8007b6e0>] (queue_work_on+0x38/0x40)
[  330.939039] [<8007b6e0>] (queue_work_on+0x38/0x40) from [<8007d568>] (queue_work+0x2c/0x58)
[  330.947401] [<8007d568>] (queue_work+0x2c/0x58) from [<803b83a4>] (snd_soc_resume+0x98/0xb8)
[  330.955852] [<803b83a4>] (snd_soc_resume+0x98/0xb8) from [<80280aa4>] (platform_pm_resume+0x2c/0x4c)
[  330.964996] [<80280aa4>] (platform_pm_resume+0x2c/0x4c) from [<80284388>] (pm_op+0xe4/0x11c)
[  330.973441] [<80284388>] (pm_op+0xe4/0x11c) from [<80284780>] (device_resume+0x78/0x13c)
[  330.981537] [<80284780>] (device_resume+0x78/0x13c) from [<802849d0>] (dpm_resume+0x144/0x194)
[  330.990154] [<802849d0>] (dpm_resume+0x144/0x194) from [<80284a2c>] (dpm_resume_end+0xc/0x18)
[  330.998692] [<80284a2c>] (dpm_resume_end+0xc/0x18) from [<8009cf18>] (suspend_devices_and_enter+0x78/0xb8)
[  331.008355] [<8009cf18>] (suspend_devices_and_enter+0x78/0xb8) from [<8009d010>] (enter_state+0xb8/0xe4)
[  331.017842] [<8009d010>] (enter_state+0xb8/0xe4) from [<8009c5b4>] (state_store+0x8c/0xc0)
[  331.026116] [<8009c5b4>] (state_store+0x8c/0xc0) from [<80223b20>] (kobj_attr_store+0x18/0x1c)
[  331.034740] [<80223b20>] (kobj_attr_store+0x18/0x1c) from [<801352ec>] (sysfs_write_file+0x104/0x184)
[  331.043969] [<801352ec>] (sysfs_write_file+0x104/0x184) from [<800e4ce8>] (vfs_write+0xb4/0x148)
[  331.052762] [<800e4ce8>] (vfs_write+0xb4/0x148) from [<800e4e4c>] (sys_write+0x40/0x70)
[  331.060781] [<800e4e4c>] (sys_write+0x40/0x70) from [<8003e380>] (ret_fast_syscall+0x0/0x30)

The commit:c4e133f ASoC: core: Don't schedule deferred_resume_work twice
commit c4e133f4e253b57e5d4409964a3b51f2d887e94b
Author: Stephen Warren <swarren@nvidia.com>
Date:   Wed May 25 14:06:41 2011 -0600

    ASoC: core: Don't schedule deferred_resume_work twice

    commit 82e14e8bdd88b69018fe757192b01dd98582905e upstream.

    For cards that have two or more DAIs, snd_soc_resume's loop over all
    DAIs ends up calling schedule_work(deferred_resume_work) once per DAI.
    Since this is the same work item each time, the 2nd and subsequent
    calls return 0 (work item already queued), and trigger the dev_err
    message below stating that a work item may have been lost.

    Solve this by adjusting the loop to simply calculate whether to run the
    resume work immediately or defer it, and then call schedule work (or not)
    one time based on that.

    Note: This has not been tested in mainline, but only in chromeos-2.6.38;
    mainline doesn't support suspend/resume on Tegra, nor does the mainline
    Tegra ASoC driver contain multiple DAIs. It has been compile-checked in
    mainline.

    Signed-off-by: Stephen Warren <swarren@nvidia.com>
    Acked-by: Liam Girdwood <lrg@ti.com>
    Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

changed the defaut behaviour for non-ac97 class which cause deferred_resume_work
was scheduled not by desire when card->num_rdt is zero.

Signed-off-by: Jason Liu <r64343@freescale.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index d5bf0158b36a..5f36274336ae 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1291,13 +1291,15 @@ int snd_soc_resume(struct device *dev)
 		struct snd_soc_dai *cpu_dai = card->rtd[i].cpu_dai;
 		ac97_control |= cpu_dai->driver->ac97_control;
 	}
-	if (ac97_control) {
-		dev_dbg(dev, "Resuming AC97 immediately\n");
-		soc_resume_deferred(&card->deferred_resume_work);
-	} else {
-		dev_dbg(dev, "Scheduling resume work\n");
-		if (!schedule_work(&card->deferred_resume_work))
-			dev_err(dev, "resume work item may be lost\n");
+	if (card->num_rtd) {
+		if (ac97_control) {
+			dev_dbg(dev, "Resuming AC97 immediately\n");
+			soc_resume_deferred(&card->deferred_resume_work);
+		} else {
+			dev_dbg(dev, "Scheduling resume work\n");
+			if (!schedule_work(&card->deferred_resume_work))
+				dev_err(dev, "resume work item may be lost\n");
+		}
 	}
 
 	return 0;