On 29-03-23, 21:23, Vignesh Raghavendra wrote: > The K3 platforms configure the DMA resources with the > help of the TI's System Firmware's Device Manager(DM) > over TISCI. The group of DMA related Resource Manager[1] > TISCI messages includes: INTA, RINGACC, UDMAP, and PSI-L. > This configuration however, does not persist in the DM > after leaving from Suspend-to-RAM state. We have to restore > the DMA channel configuration over TISCI for all configured > channels when returning from suspend. > > The TISCI resource management calls for each DMA type (UDMA, > PKTDMA, BCDMA) happen in device_free_chan_resources() and > device_alloc_chan_resources(). In pm_suspend() we store > the current udma_chan_config for channels that still have > attached clients and call device_free_chan_resources(). > In pm_resume() restore the udma_channel_config from backup > and call device_alloc_chan_resources() for those channels. > > Drivers like CPSW that use k3-udma-glue already do their own > DMA resource management so use the late system suspend/resume hooks. Applied, thanks -- ~Vinod
