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linux/sound/soc/stm
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Olivier Moysan 0d6defc7e0
ASoC: stm32: sai: manage rebind issue 
The commit e894efef9a ("ASoC: core: add support to card rebind")
allows to rebind the sound card after a rebind of one of its component.
With this commit, the sound card is actually rebound,
but may be no more functional. The following problems have been seen
with STM32 SAI driver.

1) DMA channel is not requested:

With the sound card rebind the simplified call sequence is:
stm32_sai_sub_probe
	snd_soc_register_component
		snd_soc_try_rebind_card
			snd_soc_instantiate_card
	devm_snd_dmaengine_pcm_register

The problem occurs because the pcm must be registered,
before snd_soc_instantiate_card() is called.

Modify SAI driver, to change the call sequence as follows:
stm32_sai_sub_probe
	devm_snd_dmaengine_pcm_register
	snd_soc_register_component
		snd_soc_try_rebind_card

2) DMA channel is not released:

dma_release_channel() is not called when
devm_dmaengine_pcm_release() is executed.
This occurs because SND_DMAENGINE_PCM_DRV_NAME component,
has already been released through devm_component_release().

devm_dmaengine_pcm_release() should be called before
devm_component_release() to avoid this problem.

Call snd_dmaengine_pcm_unregister() and snd_soc_unregister_component()
explicitly from SAI driver, to have the right sequence.

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Message-Id: <20200304102406.8093-1-olivier.moysan@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-04 13:18:50 +00:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile ASoC: stm32: add DFSDM DAI support 2018-01-10 10:52:05 +00:00
stm32_adfsdm.c ASoC: Fixes for v5.5 2020-01-17 15:38:56 +00:00
stm32_i2s.c ASoC: Remove dev_err() usage after platform_get_irq() 2019-08-02 12:12:31 +01:00
stm32_sai_sub.c ASoC: stm32: sai: manage rebind issue 2020-03-04 13:18:50 +00:00
stm32_sai.c ASoC: stm32: sai: clean up indentation issue 2019-10-01 12:15:06 +01:00
stm32_sai.h Linux 5.2-rc6 2019-06-26 12:39:34 +01:00
stm32_spdifrx.c ASoC: stm32: spdifrx: fix input pin state management 2019-12-24 23:56:17 +00:00