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: [<ffffffffc09d9409>] 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: [<ffffffffb45318f9>] dpm_prepare+0x209/0x460 [<ffffffffb4531b61>] dpm_suspend_start+0x11/0x60 [<ffffffffb40d3cc2>] suspend_devices_and_enter+0xb2/0x710 [<ffffffffb40d462e>] pm_suspend+0x30e/0x390 [<ffffffffb40d2eba>] state_store+0x8a/0x90 [<ffffffffb43c670f>] kobj_attr_store+0xf/0x20 [<ffffffffb42b0d97>] sysfs_kf_write+0x37/0x40 [<ffffffffb42b02bc>] kernfs_fop_write+0x11c/0x1b0 [<ffffffffb422be68>] __vfs_write+0x28/0x140 [<ffffffffb43728a8>] ? apparmor_file_permission+0x18/0x20 [<ffffffffb433b2ab>] ? security_file_permission+0x3b/0xc0 [<ffffffffb422d095>] vfs_write+0xb5/0x1a0 [<ffffffffb422e3d6>] SyS_write+0x46/0xa0 [<ffffffffb4719fbb>] entry_SYSCALL_64_fastpath+0x1e/0xad
Add proper NULL checks in the PM code of mdfld driver.
Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de --- v1->v2: drop the bogus return code from sst_soc_complete().
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..76bcb947b31c 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;