[Intel-gfx] [PATCH v3 0/5] HPD support during suspend for BXT/APL.

[Imre Deak]

On Tue, Dec 27, 2016 at 06:59:51PM +0530, Animesh Manna wrote:
> Along with below patches sharing some background details/design.
> - On BXT, Display cannot generate an interrupt when in D3.
> - Without display in D3, S0ix can be achieved, Power impact will be
> zero if d3 is blocked. PMCSR for Graphics/Display is irrelevant, as
> the power management for them is taken care by the PUNIT using RC6/DC9
> hints and *not* through PMCSR write trigger.
> 
> So solution is based on below principles:
> - Display should not be put into D3 for HPD to work.
> - With D0+DC9 we can achieve S0ix and at the same time helps to get the
> interrupt.
> - Using pci_save_state() during suspend to take control from OSPM and
> blocking D3, while resuming, giving back to OSPM by pci_restore_state(). 
> - _DSM method is used to program pmc hpd control register to enable
> hpd during suspend.
> 
> Please have a look and send your comments/suggestions.

Which platform did you test this on? I tried it on both an APL/RVP and a
BXT/Joule, but couldn't see any PCU HPD interrupts generated.

> 
> v1: Initial version sent as RFC.
> 
> v2: Updated version after addressing review comments from Imre,David.
> 
> v3: Updated version after addressing review commnets from Imre, Ville,
>     Chris.
> 
> Animesh Manna (5):
>   drm/i915/bxt: Corrected the guid for bxt.
>   drm/i915/bxt: VBT changes for hpd as wakeup feature
>   drm/i915/bxt: Added _DSM call to set HPD_CTL.
>   drm/i915/bxt: Block D3 during suspend.
>   drm/i915: Enable HPD interrupts with master ctl interrupt
> 
>  drivers/gpu/drm/i915/i915_drv.c       |  5 +++
>  drivers/gpu/drm/i915/i915_drv.h       |  3 ++
>  drivers/gpu/drm/i915/i915_irq.c       | 73 +++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/i915/i915_reg.h       |  8 ++++
>  drivers/gpu/drm/i915/intel_acpi.c     | 54 ++++++++++++++++++++++----
>  drivers/gpu/drm/i915/intel_bios.c     |  4 ++
>  drivers/gpu/drm/i915/intel_vbt_defs.h |  3 +-
>  7 files changed, 142 insertions(+), 8 deletions(-)
> 
> -- 
> 2.7.4
> 
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx