Marko Ristola wrote: > I did for the Mantis branch a working solution for mem and disk cases. > I haven't tested standby yet, but I think that it should be easy to > extend if it doesn't work yet. > > I used linux/Documentation/power/*.txt while > trying to understand how to implement suspend/resume. > > On my opinion, the easiest way to make standby+mem+disk work, is to > implement suspend() so, that you > assume that you might lose the power if the source transition is D0. > If the source transition state is another one, you just turn some power > off, but don't touch > the saved state that resume() needs. > (My implementation doesn't handle source transition at all now, because > of my limited time.) > > Then you must implement resume() so, that it assumes, that you are > recovering from a power loss. > You might try to optimize resume() by checking from the device or from > some previous kernel state, > whether the device has actually lost it's power or not. > > My Mantis suspend/resume altered too many files, and thus it isn't final > yet, > but it is a working although not perfect version. > > In Linux code, there is a more simple PCI suspend/resume implementation > in linux/drivers/pci/pci-driver.c. > > pci_device_suspend(): this does a very simple and basic PCI suspend > operation. > pci_default_resume(): this does a very simple and basic PCI resume > operation. > So I will try to learn from them some day to lessen changes in mantis_pci.c. > > My personal idea for the responsibilities is that: > pci_save_state() and pci_restore_state() and other function calls found > in pci-driver.c > will handle saving and restoring PCI state, although I absolute must > copy them into mantis_pci.c. > Then on resume, I have to restore non-pci states, I mean those that > aren't restored by > pci_restore_state(), pci_set_master() and such. In Mantis there is > according to Manu at least > tuner power setting and retuning. I don't know the working and optimally > small solution yet that > Manu requires: there is still testing to be done for me in Mantis. > > With a very small understanding, I have been able to implement a working > patch though. > > So I'd suggest for you to check out drivers/pci/pci-driver.c first to > implement similar PCI > functionality into budget-av. That might fix S2MEM and S2DISK. Or then > there is still something > more that has to be done. > > With my implementation I can use Kaffeine so, that after S2DISK, > Kaffeine will continue showing > the channel that it showed before. Kaffeine doesn't have to retune or > restart DMA transfer. > So only some frames were lost. > Kaffeine didn't work properly with USB based sound output, and thus I needed > motherboard internal sound output for the tests.
Thanks for your response. Meanwhile I had a look at Documentation/power and did more tests. For a proper suspend/restore implementation there is much more to be done. The state of the saa7146 must be saved/restored, which requires more than a few hours of work (and testing!). I put it on my todo list. Is there any way to find out the power state the system tries to enter (standby/mem/disk)? For now, I could add support for standby mode and deny any attempt to enter mem or disk supend mode. Better than nothing... CU Oliver -- ---------------------------------------------------------------- VDR Remote Plugin 0.3.9: http://www.escape-edv.de/endriss/vdr/ ---------------------------------------------------------------- _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
