[PATCH v2 1/4] drm/i915/dp: Assume panel power is off if runtime suspended
Cavitt, Jonathan
jonathan.cavitt at intel.com
Wed Oct 9 21:59:43 UTC 2024
-----Original Message-----
From: Deak, Imre <imre.deak at intel.com>
Sent: Wednesday, October 9, 2024 2:26 PM
To: Cavitt, Jonathan <jonathan.cavitt at intel.com>
Cc: intel-xe at lists.freedesktop.org; intel-gfx at lists.freedesktop.org
Subject: Re: [PATCH v2 1/4] drm/i915/dp: Assume panel power is off if runtime suspended
>
> On Wed, Oct 09, 2024 at 11:35:56PM +0300, Cavitt, Jonathan wrote:
> > -----Original Message-----
> > From: Intel-xe <intel-xe-bounces at lists.freedesktop.org> On Behalf Of Imre Deak
> > Sent: Wednesday, October 9, 2024 12:44 PM
> > To: intel-xe at lists.freedesktop.org; intel-gfx at lists.freedesktop.org
> > Subject: [PATCH v2 1/4] drm/i915/dp: Assume panel power is off if runtime suspended
> > >
> > > If the device is runtime suspended the eDP panel power is also off.
> > > Ignore a short HPD on eDP if the device is suspended accordingly,
> > > instead of checking the panel power state via the PPS registers for the
> > > same purpose. The latter involves runtime resuming the device
> > > unnecessarily, in a frequent scenario where the panel generates a
> > > spurious short HPD after disabling the panel power and the device is
> > > runtime suspended.
> > >
> > > Signed-off-by: Imre Deak <imre.deak at intel.com>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_dp.c | 5 ++++-
> > > drivers/gpu/drm/i915/intel_runtime_pm.h | 8 +++++++-
> > > drivers/gpu/drm/xe/compat-i915-headers/intel_runtime_pm.h | 8 ++++++++
> > > 3 files changed, 19 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index fbb096be02ade..3eff35dd59b8a 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -85,6 +85,7 @@
> > > #include "intel_pch_display.h"
> > > #include "intel_pps.h"
> > > #include "intel_psr.h"
> > > +#include "intel_runtime_pm.h"
> > > #include "intel_quirks.h"
> > > #include "intel_tc.h"
> > > #include "intel_vdsc.h"
> > > @@ -6054,7 +6055,9 @@ intel_dp_hpd_pulse(struct intel_digital_port *dig_port, bool long_hpd)
> > > u8 dpcd[DP_RECEIVER_CAP_SIZE];
> > >
> > > if (dig_port->base.type == INTEL_OUTPUT_EDP &&
> > > - (long_hpd || !intel_pps_have_panel_power_or_vdd(intel_dp))) {
> > > + (long_hpd ||
> > > + intel_runtime_pm_suspended(&i915->runtime_pm) ||
> > > + !intel_pps_have_panel_power_or_vdd(intel_dp))) {
> >
> > From what I'm reading, I'm fairly certain that
> > "i915->runtime_pm->kdev" is equivalent to "i915->drm.dev".
> > At least, this seems to be the case according to this comment on
> > the intel_runtime_pm struct in intel_runtime_pm.h:
> >
> > " struct device *kdev; /* points to i915->drm.dev */"
> >
> > So, "intel_runtime_pm_suspended(&i915->runtime_pm)" seems
> > to be logically equivalent to
> > "pm_runtime_suspended(i915->drm.dev)", which would mean we
> > wouldn't need to declare the new helper function
> > "intel_runtime_pm_suspended" as both want to operate
> > pm_runtime_suspended on the same relative path for their target
> > drm device.
> >
> > Though, perhaps I'm missing some other reasons we would want
> > the additional helper function besides,
>
> Yes, I was surprised too but drivers/gpu/drm/i915/intel_runtime_pm.h is
> not included by xe, even when drivers/gpu/drm/i915/display is built for
> it. IIUC for this and other headers the xe specific ones will be
> included instead from drivers/gpu/drm/xe/compat-i915-headers. Some of
> these in turn like i915_irq.h will revert back including the original
> one from drivers/gpu/drm/i915.
Sorry, let me clarify. When I said "perhaps I'm missing some other
reasons we would want the additional helper function", I was
referring to intel_runtime_pm_suspended as a whole, not just the
mirror in compat-i915-headers.
Basically, my question was why we use intel_runtime_pm_suspended,
when pm_runtime_suspended, at least at first glance, would also work
by itself?
-Jonathan Cavitt
>
> > so I won't block on this:
> >
> > Reviewed-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
> > -Jonathan Cavitt
> >
> > > /*
> > > * vdd off can generate a long/short pulse on eDP which
> > > * would require vdd on to handle it, and thus we
> > > diff --git a/drivers/gpu/drm/i915/intel_runtime_pm.h b/drivers/gpu/drm/i915/intel_runtime_pm.h
> > > index 126f8320f86eb..e22669d61e954 100644
> > > --- a/drivers/gpu/drm/i915/intel_runtime_pm.h
> > > +++ b/drivers/gpu/drm/i915/intel_runtime_pm.h
> > > @@ -96,10 +96,16 @@ intel_rpm_wakelock_count(int wakeref_count)
> > > return wakeref_count >> INTEL_RPM_WAKELOCK_SHIFT;
> > > }
> > >
> > > +static inline bool
> > > +intel_runtime_pm_suspended(struct intel_runtime_pm *rpm)
> > > +{
> > > + return pm_runtime_suspended(rpm->kdev);
> > > +}
> > > +
> > > static inline void
> > > assert_rpm_device_not_suspended(struct intel_runtime_pm *rpm)
> > > {
> > > - WARN_ONCE(pm_runtime_suspended(rpm->kdev),
> > > + WARN_ONCE(intel_runtime_pm_suspended(rpm),
> > > "Device suspended during HW access\n");
> > > }
> > >
> > > diff --git a/drivers/gpu/drm/xe/compat-i915-headers/intel_runtime_pm.h b/drivers/gpu/drm/xe/compat-i915-headers/intel_runtime_pm.h
> > > index cba587ceba1b6..274042bff1bec 100644
> > > --- a/drivers/gpu/drm/xe/compat-i915-headers/intel_runtime_pm.h
> > > +++ b/drivers/gpu/drm/xe/compat-i915-headers/intel_runtime_pm.h
> > > @@ -20,6 +20,14 @@ static inline void enable_rpm_wakeref_asserts(void *rpm)
> > > {
> > > }
> > >
> > > +static inline bool
> > > +intel_runtime_pm_suspended(struct xe_runtime_pm *pm)
> > > +{
> > > + struct xe_device *xe = container_of(pm, struct xe_device, runtime_pm);
> > > +
> > > + return pm_runtime_suspended(xe->drm.dev);
> > > +}
> > > +
> > > static inline intel_wakeref_t intel_runtime_pm_get(struct xe_runtime_pm *pm)
> > > {
> > > struct xe_device *xe = container_of(pm, struct xe_device, runtime_pm);
> > > --
> > > 2.44.2
> > >
> > >
>
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