Hi Andrey, On Fri, Aug 18, 2023 at 08:34:16PM +0300, Andrey Skvortsov wrote: > If system was suspended while camera sensor was used, data and > interrupts were still coming from sensor and that caused unstable > system. Sometimes system hanged during a resume. Use > pm_runtime_force_* helpers in order to support system suspend. > > Signed-off-by: Andrey Skvortsov <andrej.skvortzov@xxxxxxxxx> Thanks for the patch. It's not been documented really how system suspend and resume should work for complex cameras. But I don't think it can be done by drivers separately as the CSI-2 bus initialisation requires actions from both sender and receiver drivers, at particular points of time. So I think we'll need to initiate this from the driver handling DMA, just as starting and stopping streaming. Even then, there needs to be a certainty that the sensor device has resumed before streaming is started. I recall Laurent suggested device links for that purpose, but I don't think any work has been done to implement it that way. -- Kind regards, Sakari Ailus
