Could you please give a bit more context on what error you see when this happens?
Hi,
I get Oops. This is what happens with all other patches in this series and only this one reverted:
root@APL:~# rmmod snd_soc_sst_bxt_rt298 root@APL:~# rmmod snd_soc_hdac_hdmi root@APL:~# rmmod snd_soc_skl
Thanks, Amadeusz. I think the order in which the drivers are removed is what's causing the oops in your case. With SOF, the order we remove is
- rmmod sof_pci_dev
- rmmod snd_soc_sst_bxt_rt298
- rmmod snd_soc_hdac_hdmi
Well, there is nothing enforcing the order in which modules can be unloaded (and I see no reason to force it), as you can see from following excerpt, you can either start unloading from snd_soc_sst_bxt_rt298 or snd_soc_skl, and yes if you start from snd_soc_skl, there is no problem.
there is a fundamental dependency that you are ignoring: the module snd_soc_sst_bxt_rt298 is a machine driver which will be probed when snd_soc_skl creates a platform_device. Sure you can remove modules in a different order, but that's a bit of an artificial/academic exercise isn't it?
I am good with this patch. I just wanted to understand why we werent seeing this error with SOF. Sure, there's nothing enforcing the order in which modules are unloaded but there must be a logical order for testing purposes.
Pierre, can you please comment on it. I vaguely remember discussing this with you last year.
Our tests remove the modules by taking care of dependencies and it's already unveiled dozens of issues. We could add a sequence similar to Amadeusz and unbind the modules which are loaded with the creation of a platform_device (machine driver, dmic), I am just not sure how of useful this would be.