On Wed, Jul 20, 2022 at 06:51:37PM +0530, Anshuman Gupta wrote: > When DG1 gfx pci endpoint's parent upstream bridge (VSP) enters > to D3, any direct memory read from lmem returns with 0xff. > DG1 requires i915 driven runtime resume in order to read properly > from lmem, DG1 is unable to wakeup from local memory reads. > This may breaks using mmap() with lmem object on DG1 as it > relies on mercy of i915 driven runtime resume. why our disable at root_port not working to block this case? If the root power is not at D3Cold our power shouldn't be cut and our memory should be there. > > Let's not break using mmap() for lmem object on DG1. > Using pci_d3cold_disable(i915) accordingly to disable D3 for > upstream bridge. > > Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/6331 > Cc: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> > Signed-off-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx> > --- > drivers/gpu/drm/i915/intel_runtime_pm.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.c b/drivers/gpu/drm/i915/intel_runtime_pm.c > index 6ed5786bcd29..671009fd351a 100644 > --- a/drivers/gpu/drm/i915/intel_runtime_pm.c > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c > @@ -559,6 +559,7 @@ void intel_runtime_pm_enable(struct intel_runtime_pm *rpm) > struct drm_i915_private *i915 = container_of(rpm, > struct drm_i915_private, > runtime_pm); > + struct pci_dev *pdev = to_pci_dev(i915->drm.dev); > struct device *kdev = rpm->kdev; > > /* > @@ -574,6 +575,9 @@ void intel_runtime_pm_enable(struct intel_runtime_pm *rpm) > pm_runtime_set_autosuspend_delay(kdev, 10000); /* 10s */ > pm_runtime_mark_last_busy(kdev); > > + if (IS_DG1(i915)) > + pci_d3cold_disable(pdev); > + > /* > * Take a permanent reference to disable the RPM functionality and drop > * it only when unloading the driver. Use the low level get/put helpers, > @@ -607,12 +611,16 @@ void intel_runtime_pm_disable(struct intel_runtime_pm *rpm) > struct drm_i915_private *i915 = container_of(rpm, > struct drm_i915_private, > runtime_pm); > + struct pci_dev *pdev = to_pci_dev(i915->drm.dev); > struct device *kdev = rpm->kdev; > > /* Transfer rpm ownership back to core */ > drm_WARN(&i915->drm, pm_runtime_get_sync(kdev) < 0, > "Failed to pass rpm ownership back to core\n"); > > + if (IS_DG1(i915)) > + pci_d3cold_enable(pdev); > + > pm_runtime_dont_use_autosuspend(kdev); > > if (!rpm->available) > -- > 2.26.2 >
