[Intel-gfx] [PATCH v4 0/5] HPD support during suspend for BXT/APL.

[Animesh Manna]

Hi,


On 6/27/2017 5:31 PM, David Weinehall wrote:
> On Mon, Jun 12, 2017 at 08:54:02PM +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.
> Does this apply to GLK as well?
Yes, as per bspec this apply for GLK as well.

Regards,
Animesh
>
>> 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.
>>
>> 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.
>>
>> v4: New version updated after bios changes on APL platform.
>>
>> 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         | 69 +++++++++++++++++++++++++++++++--
>>   drivers/gpu/drm/i915/i915_reg.h         |  8 ++++
>>   drivers/gpu/drm/i915/intel_acpi.c       | 59 ++++++++++++++++++++++++----
>>   drivers/gpu/drm/i915/intel_bios.c       |  4 ++
>>   drivers/gpu/drm/i915/intel_runtime_pm.c |  3 +-
>>   drivers/gpu/drm/i915/intel_vbt_defs.h   |  3 +-
>>   8 files changed, 141 insertions(+), 13 deletions(-)
>>
>> -- 
>> 1.9.1
>>
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