On Tue, Jun 18, 2019 at 8:39 PM Fabio Estevam <feste...@gmail.com> wrote: > > On Tue, Jun 18, 2019 at 11:46 AM Pintu Agarwal <pintu.p...@gmail.com> wrote: > > > Thank you so much for your reply. > > Yes, I already checked the latest mainline kernel changes until 5.2-**. > > I see that there are many cleanup related changes, but still I see > > that suspend/resume functions are missing in dw_hdmi-imx driver. > > Please see this recently submitted patch: > https://lore.kernel.org/patchwork/patch/1084057/ > Okay. Thank you for this reference. This can be definitely helpful. But a quick look may be feel, this is slightly different. Anyways, I will have a deeper look.
> > So, I am trying to implement myself. > > Also, I see that suspend/resume is missing even in : > > drivers/gpu/drm/imx/ipuv3-crtc.c > > I am trying this also (not sure if we need this as well). > > > > Can you point out some specific patches which can be helpful ? > > > > Currently, what I observed is that hdmi bind() functions are not getting > > called. > > Not sure who is responsible for triggering this bind function. > > Or, irq remains disabled after resume, and we need to enable it back > > again (but how ?) > > Or, we may need to enable vblank events and thus irqs can be enabled. > > > > So, I am exploring many possibilities. > > If you have any suggestions please let me know. > > The suggestion I have is to try to use latest mainline kernel. If you > see any issues with it, please report. > > The combination you mentioned in a prior thread (kernel 3.10 + > backported drm patches 4.9) is not really something the community can > help you. You can think that the version I am using right now is almost 4.9 itself. Upgrading again to higher kernel version is again difficult, also customer does not want it. BTW, I am not talking about runtime suspend/resume. I know it works normally. I just need some approach and pointers. Like someone said rightly, I may need to re-implement bind() function again in resume path. I already tried doing hdmi_power_on/off and with that I could invoke hdmi_setup() function, but the system hang after that. Another approach I tried is, installing hdmi {dw-hdmi.ko, dw_hdmi-imx.ko} as a module, just after the resume. With this also system hangs during installation of dw_hdmi-imx.ko at below location: imx_drm_driver_load(..) | |--> component_bind_all(...) | |-> component_bind(ipu) | | ipu_drm_bind(..) | |-> ipu_crtc_init(..) | |-> ipu_plane_irq(..) | | ----> << __HANGS HERE__ >> | |-> devm_request_irq(ipu_irq_handler) So, ipu_drm_bind() never returns, and hangs. ---------- So, my question is, which approach is better (as a first trial): 1) Installing hdmi as a module, after resume ? 2) Or, implementing the suspend/resume itself ?