On Wed, May 20, 2020 at 8:38 PM Mark Brown <broonie@xxxxxxxxxx> 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
