From 2fc995a87f2efcd803438f07bfecd35cc3d90d32 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Fri, 25 Nov 2016 16:54:06 +0100 Subject: [PATCH] ASoC: intel: Fix crash at suspend/resume without card registration When ASoC Intel SST Medfield driver is probed but without codec / card assigned, it causes an Oops and freezes the kernel at suspend/resume, PM: Suspending system (freeze) Suspending console(s) (use no_console_suspend to debug) BUG: unable to handle kernel NULL pointer dereference at 0000000000000018 IP: [] sst_soc_prepare+0x19/0xa0 [snd_soc_sst_mfld_platform] Oops: 0000 [#1] PREEMPT SMP CPU: 0 PID: 1552 Comm: systemd-sleep Tainted: G W 4.9.0-rc6-1.g5f5c2ad-default #1 Call Trace: [] dpm_prepare+0x209/0x460 [] dpm_suspend_start+0x11/0x60 [] suspend_devices_and_enter+0xb2/0x710 [] pm_suspend+0x30e/0x390 [] state_store+0x8a/0x90 [] kobj_attr_store+0xf/0x20 [] sysfs_kf_write+0x37/0x40 [] kernfs_fop_write+0x11c/0x1b0 [] __vfs_write+0x28/0x140 [] ? apparmor_file_permission+0x18/0x20 [] ? security_file_permission+0x3b/0xc0 [] vfs_write+0xb5/0x1a0 [] SyS_write+0x46/0xa0 [] entry_SYSCALL_64_fastpath+0x1e/0xad Add proper NULL checks in the PM code of mdfld driver. Signed-off-by: Takashi Iwai Acked-by: Vinod Koul Signed-off-by: Mark Brown Cc: --- sound/soc/intel/atom/sst-mfld-platform-pcm.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/sound/soc/intel/atom/sst-mfld-platform-pcm.c b/sound/soc/intel/atom/sst-mfld-platform-pcm.c index 25c6d87c818e..f5a8050351b5 100644 --- a/sound/soc/intel/atom/sst-mfld-platform-pcm.c +++ b/sound/soc/intel/atom/sst-mfld-platform-pcm.c @@ -771,6 +771,9 @@ static int sst_soc_prepare(struct device *dev) struct sst_data *drv = dev_get_drvdata(dev); struct snd_soc_pcm_runtime *rtd; + if (!drv->soc_card) + return 0; + /* suspend all pcms first */ snd_soc_suspend(drv->soc_card->dev); snd_soc_poweroff(drv->soc_card->dev); @@ -793,6 +796,9 @@ static void sst_soc_complete(struct device *dev) struct sst_data *drv = dev_get_drvdata(dev); struct snd_soc_pcm_runtime *rtd; + if (!drv->soc_card) + return; + /* restart SSPs */ list_for_each_entry(rtd, &drv->soc_card->rtd_list, list) { struct snd_soc_dai *dai = rtd->cpu_dai; -- 2.20.1