Hi, Adam, > -----Original Message----- > From: Adam Thomson <Adam.Thomson.Opensource@xxxxxxxxxxx> > Sent: Thursday, July 30, 2020 10:54 AM > To: Zhi, Yong <yong.zhi@xxxxxxxxx>; alsa-devel@xxxxxxxxxxxxxxxx; > broonie@xxxxxxxxxx > Cc: pierre-louis.bossart@xxxxxxxxxxxxxxx; Adam Thomson > <Adam.Thomson.Opensource@xxxxxxxxxxx> > Subject: RE: [PATCH] ASoC: da7219: Fix general protection fault in > da7219_register_dai_clks > > On 30 July 2020 15:04, Yong Zhi wrote: > > > clkdev_drop(cl) does not null the removed cl, if > > da7219_register_dai_clks() entered again after card removal, > > devm_clk_register() will return -EEXIST, the goto err to clkdev_drop() will > trigger board reboot. > > > > Test commands: > > modprobe -r snd_sof_pci > > modprobe snd_sof_pci > > > > The oops looks like: > > > > da7219 i2c-DLGS7219:00: Using default DAI clk names: da7219-dai-wclk, > > da7219- dai-bclk > > da7219 i2c-DLGS7219:00: Failed to register da7219-dai-wclk: -17 > > general protection fault: 0000 [#1] PREEMPT SMP NOPTI > > RIP: 0010:clkdev_drop+0x20/0x52 > > Call Trace: > > da7219_probe+0x52e/0x6dc [snd_soc_da7219] > > soc_probe_component+0x206/0x3a1 > > snd_soc_bind_card+0x4ee/0x9a6 > > devm_snd_soc_register_card+0x48/0x7b > > audio_probe+0x1f0/0x221 [snd_soc_sof_da7219_max98373] > > platform_drv_probe+0x89/0xa2 > > really_probe+0x129/0x30d > > driver_probe_device+0x59/0xec > > ? driver_sysfs_remove+0x55/0x55 > > bus_for_each_drv+0xa1/0xdc > > __device_attach+0xc2/0x146 > > bus_probe_device+0x32/0x97 > > device_add+0x311/0x3b4 > > platform_device_add+0x184/0x1eb > > > > Fix by marking (nullifying) the da7219->dai_clks_lookup[i] after > > clkdev_drop(). > > > > Signed-off-by: Yong Zhi <yong.zhi@xxxxxxxxx> > > --- > > sound/soc/codecs/da7219.c | 4 +++- > > 1 file changed, 3 insertions(+), 1 deletion(-) > > > > diff --git a/sound/soc/codecs/da7219.c b/sound/soc/codecs/da7219.c > > index 153ea30b5a8f..54da7cfbb5f4 100644 > > --- a/sound/soc/codecs/da7219.c > > +++ b/sound/soc/codecs/da7219.c > > @@ -2369,8 +2369,10 @@ static void da7219_remove(struct > > snd_soc_component *component) > > > > #ifdef CONFIG_COMMON_CLK > > for (i = DA7219_DAI_NUM_CLKS - 1; i >= 0; --i) { > > - if (da7219->dai_clks_lookup[i]) > > + if (da7219->dai_clks_lookup[i]) { > > clkdev_drop(da7219->dai_clks_lookup[i]); > > + da7219->dai_clks_lookup[i] = NULL; > > + } > > It seems to me that devm_* functions should have freed up everything when the > codec module was removed. I can only assume the codec isn't being removed in > your test hence devm is never freeing the clock resource and is why you're > getting -EEXIST. Is this the case and is your use-case expected behaviour? It's > not something that has been reported previously so am keen to understand > exactly what's happening here. > > > } > > #endif > > When the card was uninstalled with modprobe -r, the da7219 codec was not removed, only component da7219_remove() is invoked, do you suggest the component driver probe and remove has to happen with da7219_i2_driver probe and remove together? Thanks for the code review. > > -- > > 2.7.4