Hi Zhenhua, On 8/13/2024 10:56 AM, Zhenhua Huang wrote: > > On 2024/8/13 15:20, Pranjal Shrivastava wrote: >> On Tue, Aug 13, 2024 at 10:37:33AM +0800, Zhenhua Huang wrote: >>> >>> On 2024/8/12 21:25, Pranjal Shrivastava wrote: >>>> On Tue, Jul 30, 2024 at 06:30:43PM +0800, Zhenhua Huang wrote: >>>>> TBU driver has no runtime pm support now, adding pm_runtime_enable() >>>>> seems to be useless. Remove it. >>>>> >>>>> Signed-off-by: Zhenhua Huang <quic_zhenhuah@xxxxxxxxxxx> [..] >> I agree that there are no pm_runtime_suspend/resume calls within the TBU >> driver. I'm just trying to understand why was pm_runtime enabled here >> earlier (since it's not implemented) in order to ensure that removing it >> doesn't cause further troubles? > > See above my assumption, need Georgi to comment but. Thank you for looking at the code! Your assumptions are mostly correct, but if you try this patch on a real sdm845 device you will notice some issues. So it's actually needed to re-configure the power-domains, three of which (MMNOC GDSCs) are requiring this because of a HW bug. I should have put a comment in the code to avoid confusion, but it took me some time to confirm it. I have sent a patch to handle this more cleanly: https://lore.kernel.org/lkml/20240813120015.3242787-1-quic_c_gdjako@xxxxxxxxxxx So we should not remove the runtime pm calls until some version of the above patch gets merged. Thanks, Georgi >> I see Georgi added it as a part of >> https://lore.kernel.org/all/20240704010759.507798-1-quic_c_gdjako@xxxxxxxxxxx/ >> >> But I'm unsure why was it required to fix that bug? > > I'm just thinking it is dead code and want to see if my understanding is correct.
