ALSA: hda: fix crashes in remove path

SErrors and kernel panic are seen when driver is unloaded.

Following is the trace during hda_tegra_remove_sysfs,
 [<ffffff800104ea5c>] hda_tegra_remove_sysfs.isra.1+0x84/0xa8
 [<ffffff8008761580>] platform_drv_remove+0x30/0x50
 [<ffffff800875f1f0>] driver_detach+0xc8/0xd0
 [<ffffff800875ddb4>] bus_remove_driver+0x64/0ister+0x34/0x58
 [<ffffff8008761688>] platform_driver_unregister+0x20/0x30
 [<ffffff80081524b8>] SyS_delete_module+0x1c8/0x210
 [<ffffff8008083040>] el0_svc_naked+0x<2>
 CPU3: SError detected, daif=1c0, spsr=0x40c000c5, mpidr=80000101, esr=be000000
 CPU1: SError detected, daif=140, spsr=0x20400145, mpidr=80000001, esr=be000000

Following trace is seen in snd_card_free path,
 PC is at hda_tegra_readw+0x20/0x38 [snd_hda_tegra]
 LR is at snd_hdac_bus_send_c3e07498f8 x26: ffffffc3a7baf904
 x25: ffffff8009d78000 x24: ffffff8009f810d8
 x23: ffffff9709] x15: aaaaaaaaaaaaaaab x14: 0000000000000002
 x13: 0000000000000003 x12: 0000000000000018
 x9 : 0000000000000000 x8 : 0001000000000000
 x7 : 0000000000000030 x6 : ffffffc3ede8c160
 x3 : 0000000000010000 x2 : 0000000000010000
 x1 : ffffff800104e0b8 x0 : 000000000000
 [<ffffff8008d1e808>]snd_hdac_bus_send_cmd+0x88/0x100
 [<ffffff8008ccf294>] azx_send_cmd.part.7+0x144/0x240
 [<ffffff8008d1c72c>] snd_hdac_codec_read+0x6c/0xb0
 [<ffffff8008cc6a60>] hda_call_codec_resume+0x50/0x138
 [<ffffff8008cc6b84>] hda_codec_run2c/0x40
 [<ffffff800875da24>] bus_remove_device+0xe4/0x160
 [<ffffff80087594e4>] device_del181.929313]
 [<ffffff8008ca120c>] snd_device_free_all+0x34/0x50
 [<ffffff8008c9a1dc>] release_card_device+0x2ccard_free+0x70/0xa8
 [<ffffff800104eadc>] hda_tegra_remove+0x4c/0x58 [snd_hda_tegra]
 [<ffffff800875ff74>] driver_unregister+0x34/0x58
 [<ffffff8008761688>] platfvc_naked+0x34/0x38

This patch adds following to avoid such errors.
- after kobject_put() set obj reference to NULL
- free sound card first and then call runtime suspend

Bug 200453666

Change-Id: I55c58661890734dd0718fec8e0b2b944ef8d4484
Signed-off-by: spujar <spujar@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1925280
(cherry picked from commit 1fff9e75c6202d1657d4d0dffab4df633075ef80)
Reviewed-on: https://git-master.nvidia.com/r/1935132
GVS: Gerrit_Virtual_Submit
Reviewed-by: Mohan Kumar D <mkumard@nvidia.com>
Reviewed-by: Ravindra Lokhande <rlokhande@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 11 insertions, 4 deletions

diff --git a/sound/pci/hda/hda_tegra.c b/sound/pci/hda/hda_tegra.c
index d1b37d959..08f0ce256 100644
--- a/sound/pci/hda/hda_tegra.c
+++ b/sound/pci/hda/hda_tegra.c
@@ -722,6 +722,7 @@ static int hda_tegra_create_sysfs(struct hda_tegra *hda)
                         dev_info(hda->dev, "error in getting switch name"
                                 " for hda_pcm_id(%d)\n", apcm->info->device);
                         kobject_put(pcm_dev->kobj);
+                        pcm_dev->kobj = NULL;
                         continue;
                 }
 
@@ -760,9 +761,11 @@ static void hda_tegra_remove_sysfs(struct device *dev)
                         sysfs_remove_file(pcm_dev->kobj,
                                 &pcm_dev->name_attr.attr);
                         kobject_put(pcm_dev->kobj);
+                        pcm_dev->kobj = NULL;
                 }
         }
         kobject_put(hda->kobj);
+        hda->kobj = NULL;
 }
 
 static void hda_tegra_probe_work(struct work_struct *work)
@@ -831,14 +834,18 @@ out_free:
 
 static int hda_tegra_remove(struct platform_device *pdev)
 {
-        pm_runtime_disable(&pdev->dev);
-        if (!pm_runtime_status_suspended(&pdev->dev))
-                hda_tegra_runtime_suspend(&pdev->dev);
+        int ret;
 
         /* remove sysfs files */
         hda_tegra_remove_sysfs(&pdev->dev);
 
-        return snd_card_free(dev_get_drvdata(&pdev->dev));
+        ret = snd_card_free(dev_get_drvdata(&pdev->dev));
+
+        pm_runtime_disable(&pdev->dev);
+        if (!pm_runtime_status_suspended(&pdev->dev))
+                hda_tegra_runtime_suspend(&pdev->dev);
+
+        return ret;
 }
 
 static void hda_tegra_shutdown(struct platform_device *pdev)