On Wed, May 20, 2020 at 8:38 PM Mark Brown broonie@kernel.org wrote:
On Wed, May 20, 2020 at 07:22:19PM +0800, Shengjiu Wang wrote:
I see some driver also request dma channel in open() or hw_params(). how can they avoid the defer probe issue? for example： sound/arm/pxa2xx-pcm-lib.c sound/soc/sprd/sprd-pcm-dma.c
Other drivers having problems means those drivers should be fixed, not that we should copy the problems. In the case of the PXA driver that's very old code which predates deferred probe by I'd guess a decade.
Thanks.
For the FE-BE case, do you have any suggestion for how fix it?
With DMA1->ASRC->DMA2->ESAI case, the DMA1->ASRC->DMA2 is in FE, ESAI is in BE. When ESAI drvier probe, DMA3 channel is created with ESAI's "dma:tx" (DMA3 channel is not used in this FE-BE case). When FE-BE startup, DMA2 channel is created, it needs the ESAI's "dma:tx", so the warning comes out.
best regards wang shengjiu