Hi On 01/14/2015 10:43 PM, Fabio Estevam wrote:
On Wed, Jan 14, 2015 at 10:57 AM, Lars-Peter Clausen lars@metafoo.de wrote:
My personal opinion on this is that disallowing module removal while a driver registered by the module when is in use, while there is no technical reason to do so, is a anti-feature. Whether in ALSA or elsewhere.
But looking at the source it seems that this is a core feature of ALSA and at least for the card module itself it will do the ref-counting when a stream is started/stopped. And we even support setting the owner of a card in ASoC. It's just that pretty much no ASoC card driver bothers to set the owner field in the snd_soc_card struct. So this particular problem can be fixed by updating the imx-wm8962 driver to set the owner field.
Thanks, Lars_Peter. This fixes the issue:
root@freescale /$ modprobe -r snd_soc_imx_wm8962 modprobe: can't unload module snd_soc_imx_wm8962: Resource temporarily unavailable
Will send a patch with your suggestion soon.
I think by set owner field in imx_wm8962 machine driver can fix the crash I saw on sabreSD board, but as this is a generic issue which I suppose should exist on other boards with different machine drivers.
Can we have a more generic fix to this issue? Or shall we set owner field for all machine drivers?
Thanks, Jiada