On Wed, Feb 06, 2019 at 11:11:03AM +0100, Sylwester Nawrocki wrote: > On 2/6/19 10:46, Sylwester Nawrocki wrote: > > On 2/5/19 22:16, Krzysztof Kozlowski wrote: > >> Bisect pointed to commit: > >> commit 078a85f2806f0ffd11289009462a6a390f9adb5c > >> Author: Charles Keepax <ckeepax@xxxxxxxxxxxxxxxxxxxxx> > >> Date: Thu Jan 31 13:30:18 2019 +0000 > >> ASoC: dapm: Only power up active channels from a DAI > >> > >> as a bad commit for NULL pointer on my Odroid XU3 and Odroid U3 board when > >> doing "aplay /usr/share/sounds/alsa/Front_Right.wav". > >> > >> 1. Arch ARM Linux > >> 2. exynos_defconfig > >> 3. Odroid U3, XU3, Exynos SoC, ARMv7 > >> > >> Last address is in calltrace: > >> c079552c > >> dapm_update_dai_unlocked > >> sound/soc/soc-dapm.c:2586 > > > > Thanks for bisecting this, I ran into same issue last night and I'm starting > > to debug this now. I have added some debug prints and it looks like it oopses > > on NULL playback_widget of the dummy DAI. > > > > [ 30.701182] hdmi-audio-codec hdmi-audio-codec.0.auto: Update DAI routes for i2s-hifi playback > > [ 30.709630] dapm_update_dai_unlocked:2586 w=8bd27d28 > > [ 30.714403] dapm_update_dai_unlocked:2594 w=8bd27d28 > > [ 30.724688] max98090 5-0010: Update DAI routes for HiFi playback > > [ 30.730163] dapm_update_dai_unlocked:2586 w=3fc942af > > [ 30.735154] dapm_update_dai_unlocked:2594 w=3fc942af > > [ 30.745051] snd-soc-dummy snd-soc-dummy: Update DAI routes for snd-soc-dummy-dai playback > > [ 30.753128] dapm_update_dai_unlocked:2586 w= (null) > > [ 30.758114] Unable to handle kernel NULL pointer dereference at virtual address 0000007c > > With a change as below there is no oops and everything works again, > but I'm not sure this is a proper fix. > I think this is the proper fix, if we have DAIs which don't have capture/playback widgets then there should be no parts of the DAPM graph that need updated in relation to the number of channels, so skipping the processing seems fine. Thanks, Charles > diff --git a/sound/soc/soc-dapm.c b/sound/soc/soc-dapm.c > index 5b74dffc9c11..111a23a9708a 100644 > --- a/sound/soc/soc-dapm.c > +++ b/sound/soc/soc-dapm.c > @@ -2580,6 +2580,9 @@ static int dapm_update_dai_unlocked(struct snd_pcm_substream *substream, > else > w = dai->capture_widget; > > + if (!w) > + return 0; > + > dev_dbg(dai->dev, "Update DAI routes for %s %s\n", dai->name, > dir == SNDRV_PCM_STREAM_PLAYBACK ? "playback" : "capture"); > > -- > Thanks, > Sylwester
