On 2/27/2024 6:22 PM, Baochen Qiang wrote: > MHI devices may not be destroyed during suspend/hibernation, so need > to unprepare/prepare MHI channels throughout the transition, this is > done by adding suspend/resume callbacks. > > The suspend callback is called in the late suspend stage, this means > MHI channels are still alive at suspend stage, and that makes it > possible for an MHI controller driver to communicate with others over > those channels at suspend stage. While the resume callback is called > in the early resume stage, for a similar reason. > > Also note that we won't do unprepare/prepare when MHI device is in > suspend state because it's pointless if MHI is only meant to go through > a suspend/resume transition, instead of a complete power cycle. > > Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30 > > Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx> Reviewed-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>