On Sun, 29 Dec 2019 16:04:54 +0100, Dmitry Osipenko wrote: > > The rt5640->jack is NULL if jack is already disabled at the time of > driver's module unloading. > > Unable to handle kernel NULL pointer dereference at virtual address 00000024 > ... > (rt5640_set_jack [snd_soc_rt5640]) from [<bf86f7ed>] (snd_soc_component_set_jack+0x11/0x1c [snd_soc_core]) > (snd_soc_component_set_jack [snd_soc_core]) from [<bf8675cf>] (soc_remove_component+0x1b/0x54 [snd_soc_core]) > (soc_remove_component [snd_soc_core]) from [<bf868859>] (soc_cleanup_card_resources+0xad/0x1cc [snd_soc_core]) > (soc_cleanup_card_resources [snd_soc_core]) from [<bf86945f>] (snd_soc_unregister_card+0x47/0x78 [snd_soc_core]) > (snd_soc_unregister_card [snd_soc_core]) from [<bf8b4013>] (tegra_rt5640_remove+0x13/0x1c [snd_soc_tegra_rt5640]) > (tegra_rt5640_remove [snd_soc_tegra_rt5640]) from [<c0516d2f>] (platform_drv_remove+0x17/0x24) > (platform_drv_remove) from [<c0515aed>] (device_release_driver_internal+0x95/0x114) > (device_release_driver_internal) from [<c0515bd9>] (driver_detach+0x4d/0x90) > (driver_detach) from [<c0514d59>] (bus_remove_driver+0x31/0x70) > (bus_remove_driver) from [<bf8b4215>] (tegra_rt5640_driver_exit+0x9/0xdf4 [snd_soc_tegra_rt5640]) > (tegra_rt5640_driver_exit [snd_soc_tegra_rt5640]) from [<c019336f>] (sys_delete_module+0xe7/0x184) > (sys_delete_module) from [<c0101001>] (ret_fast_syscall+0x1/0x28) > > Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx> > --- > sound/soc/codecs/rt5640.c | 22 ++++++++++++++-------- > 1 file changed, 14 insertions(+), 8 deletions(-) > > diff --git a/sound/soc/codecs/rt5640.c b/sound/soc/codecs/rt5640.c > index adbae1f36a8a..b245c44cafbc 100644 > --- a/sound/soc/codecs/rt5640.c > +++ b/sound/soc/codecs/rt5640.c > @@ -2432,16 +2432,22 @@ static void rt5640_disable_jack_detect(struct snd_soc_component *component) > { > struct rt5640_priv *rt5640 = snd_soc_component_get_drvdata(component); > > - disable_irq(rt5640->irq); > - rt5640_cancel_work(rt5640); > + /* > + * soc_remove_component() force-disables jack and thus rt5640->jack > + * could be NULL at the time of driver's module unloading. > + */ > + if (rt5640->jack) { > + disable_irq(rt5640->irq); > + rt5640_cancel_work(rt5640); > > - if (rt5640->jack->status & SND_JACK_MICROPHONE) { > - rt5640_disable_micbias1_ovcd_irq(component); > - rt5640_disable_micbias1_for_ovcd(component); > - snd_soc_jack_report(rt5640->jack, 0, SND_JACK_BTN_0); > - } > + if (rt5640->jack->status & SND_JACK_MICROPHONE) { > + rt5640_disable_micbias1_ovcd_irq(component); > + rt5640_disable_micbias1_for_ovcd(component); > + snd_soc_jack_report(rt5640->jack, 0, SND_JACK_BTN_0); > + } > > - rt5640->jack = NULL; > + rt5640->jack = NULL; > + } > } I guess it's simpler just returning if rt5640->jack is already NULL. --- a/sound/soc/codecs/rt5640.c +++ b/sound/soc/codecs/rt5640.c @@ -2432,6 +2432,10 @@ static void rt5640_disable_jack_detect(struct snd_soc_component *component) { struct rt5640_priv *rt5640 = snd_soc_component_get_drvdata(component); + /* already disabled? */ + if (!rt5640->jack) + return; + disable_irq(rt5640->irq); rt5640_cancel_work(rt5640); thanks, Takashi _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx https://mailman.alsa-project.org/mailman/listinfo/alsa-devel