Re: [PATCH v2 3/3] drm/i915: Add support for integrated privacy screens

Rajat Jain
2019-12-20T20:39:59Z

HI Jani,

On Thu, Dec 5, 2019 at 1:34 AM Rajat Jain <rajatja@google.com> wrote:
>
> On Wed, Nov 20, 2019 at 7:04 AM Jani Nikula <jani.nikula@linux.intel.com> wrote:
> >
> > On Mon, 04 Nov 2019, Rajat Jain <rajatja@google.com> wrote:
> > > Certain laptops now come with panels that have integrated privacy
> > > screens on them. This patch adds support for such panels by adding
> > > a privacy-screen property to the intel_connector for the panel, that
> > > the userspace can then use to control and check the status.
> > >
> > > Identifying the presence of privacy screen, and controlling it, is done
> > > via ACPI _DSM methods.
> > >
> > > Currently, this is done only for the Intel display ports. But in future,
> > > this can be done for any other ports if the hardware becomes available
> > > (e.g. external monitors supporting integrated privacy screens?).
> > >
> > > Signed-off-by: Rajat Jain <rajatja@google.com>
> > > Change-Id: Ic9ff07fc4a50797d2d0dfb919f11aa0821a4b548
> > > ---
> > > v2: Formed by splitting the original patch into multiple patches.
> > > - All code has been moved into i915 now.
> > > - Privacy screen is a i915 property
> > > - Have a local state variable to store the prvacy screen. Don't read
> > > it from hardware.
> > >
> > > drivers/gpu/drm/i915/Makefile | 3 +-
> > > drivers/gpu/drm/i915/display/intel_atomic.c | 13 +++-
> > > .../gpu/drm/i915/display/intel_connector.c | 35 ++++++++++
> > > .../gpu/drm/i915/display/intel_connector.h | 1 +
> > > .../drm/i915/display/intel_display_types.h | 4 ++
> > > drivers/gpu/drm/i915/display/intel_dp.c | 5 ++
> > > .../drm/i915/display/intel_privacy_screen.c | 70 +++++++++++++++++++
> > > .../drm/i915/display/intel_privacy_screen.h | 25 +++++++
> > > include/uapi/drm/i915_drm.h | 14 ++++
> > > 9 files changed, 166 insertions(+), 4 deletions(-)
> > > create mode 100644 drivers/gpu/drm/i915/display/intel_privacy_screen.c
> > > create mode 100644 drivers/gpu/drm/i915/display/intel_privacy_screen.h
> > >
> > > diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> > > index 2587ea834f06..3589ebcf27bc 100644
> > > --- a/drivers/gpu/drm/i915/Makefile
> > > +++ b/drivers/gpu/drm/i915/Makefile
> > > @@ -185,7 +185,8 @@ i915-y += \
> > > display/intel_tc.o
> > > i915-$(CONFIG_ACPI) += \
> > > display/intel_acpi.o \
> > > - display/intel_opregion.o
> > > + display/intel_opregion.o \
> > > + display/intel_privacy_screen.o
> >
> > Mmmh, wonder if there'll be non-ACPI based privacy screens. I guess we
> > can sort this out then. *shrug*
> >
> > > i915-$(CONFIG_DRM_FBDEV_EMULATION) += \
> > > display/intel_fbdev.o
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > index d3fb75bb9eb1..378772d3449c 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > @@ -37,6 +37,7 @@
> > > #include "intel_atomic.h"
> > > #include "intel_display_types.h"
> > > #include "intel_hdcp.h"
> > > +#include "intel_privacy_screen.h"
> > > #include "intel_sprite.h"
> > >
> > > /**
> > > @@ -57,11 +58,14 @@ int intel_digital_connector_atomic_get_property(struct drm_connector *connector,
> > > struct drm_i915_private *dev_priv = to_i915(dev);
> > > struct intel_digital_connector_state *intel_conn_state =
> > > to_intel_digital_connector_state(state);
> > > + struct intel_connector *intel_connector = to_intel_connector(connector);
> > >
> > > if (property == dev_priv->force_audio_property)
> > > *val = intel_conn_state->force_audio;
> > > else if (property == dev_priv->broadcast_rgb_property)
> > > *val = intel_conn_state->broadcast_rgb;
> > > + else if (property == intel_connector->privacy_screen_property)
> > > + *val = intel_conn_state->privacy_screen_status;
> > > else {
> > > DRM_DEBUG_ATOMIC("Unknown property [PROP:%d:%s]\n",
> > > property->base.id, property->name);
> > > @@ -89,15 +93,18 @@ int intel_digital_connector_atomic_set_property(struct drm_connector *connector,
> > > struct drm_i915_private *dev_priv = to_i915(dev);
> > > struct intel_digital_connector_state *intel_conn_state =
> > > to_intel_digital_connector_state(state);
> > > + struct intel_connector *intel_connector = to_intel_connector(connector);
> > >
> > > if (property == dev_priv->force_audio_property) {
> > > intel_conn_state->force_audio = val;
> > > return 0;
> > > - }
> > > -
> > > - if (property == dev_priv->broadcast_rgb_property) {
> > > + } else if (property == dev_priv->broadcast_rgb_property) {
> > > intel_conn_state->broadcast_rgb = val;
> > > return 0;
> > > + } else if (property == intel_connector->privacy_screen_property) {
> > > + intel_privacy_screen_set_val(intel_connector, val);
> > > + intel_conn_state->privacy_screen_status = val;
> > > + return 0;
> > > }
> > >
> > > DRM_DEBUG_ATOMIC("Unknown property [PROP:%d:%s]\n",
> > > diff --git a/drivers/gpu/drm/i915/display/intel_connector.c b/drivers/gpu/drm/i915/display/intel_connector.c
> > > index 308ec63207ee..3ccbf52aedf9 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_connector.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_connector.c
> > > @@ -281,3 +281,38 @@ intel_attach_colorspace_property(struct drm_connector *connector)
> > > drm_object_attach_property(&connector->base,
> > > connector->colorspace_property, 0);
> > > }
> > > +
> > > +static const struct drm_prop_enum_list privacy_screen_enum[] = {
> > > + { PRIVACY_SCREEN_DISABLED, "Disabled" },
> > > + { PRIVACY_SCREEN_ENABLED, "Enabled" },
> > > +};
> > > +
> > > +/**
> > > + * intel_attach_privacy_screen_property -
> > > + * create and attach the connecter's privacy-screen property. *
> > > + * @connector: connector for which to init the privacy-screen property
> > > + *
> > > + * This function creates and attaches the "privacy-screen" property to the
> > > + * connector. Initial state of privacy-screen is set to disabled.
> > > + */
> > > +void
> > > +intel_attach_privacy_screen_property(struct drm_connector *connector)
> > > +{
> > > + struct intel_connector *intel_connector = to_intel_connector(connector);
> > > + struct drm_property *prop;
> > > +
> > > + if (!intel_connector->privacy_screen_property) {
> > > + prop = drm_property_create_enum(connector->dev,
> > > + DRM_MODE_PROP_ENUM,
> > > + "privacy-screen",
> > > + privacy_screen_enum,
> > > + ARRAY_SIZE(privacy_screen_enum));
> > > + if (!prop)
> > > + return;
> > > +
> > > + intel_connector->privacy_screen_property = prop;
> > > + }
> > > +
> > > + drm_object_attach_property(&connector->base, prop,
> > > + PRIVACY_SCREEN_DISABLED);
> > > +}
> >
> > I think this should be a drm core level property in drm_connector.[ch]
> > so that *all* drivers would use the same thing for privacy screens. Not
> > i915 specific.
> >
> > I think this is the biggest issue in the patch series.
>
> I actually would be happy to make it a drm_connector property, like I
> had in my original patch series. I changed it to i915 specific because
> it seemed to me based on the comments that the general sentiment is
> that anything to do with acpi should be in i915.
>
> Note that the privacy screen property essentially needs an ACPI handle
> to work on, so if I were to move the property into drm_connector, I'd
> likely rename the intel_privacy_screen* code to drm_privacy_screen*
> code, and it'll still operate on an ACPI handle (stored in
> drm_connector structure). The i915's job will then be to lookup that
> ACPI handle (because lookup requires display index) and populate it in
> drm_connector. Does this sound OK?

Wondering if you ever got my email. I found out this week that I
needed to be a member of intel-gfx mailing list otherwise my patches
won't show up on patchwork.freedesktop.org. I'm now a member, and I
have posted my latest patchset at:

https://patchwork.freedesktop.org/patch/346275/

I'd appreciate if you could please review and comment and provide your
valuable suggestions.

Thanks & Best Regards,

Rajat

>
> >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_connector.h b/drivers/gpu/drm/i915/display/intel_connector.h
> > > index 93a7375c8196..61005f37a338 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_connector.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_connector.h
> > > @@ -31,5 +31,6 @@ void intel_attach_force_audio_property(struct drm_connector *connector);
> > > void intel_attach_broadcast_rgb_property(struct drm_connector *connector);
> > > void intel_attach_aspect_ratio_property(struct drm_connector *connector);
> > > void intel_attach_colorspace_property(struct drm_connector *connector);
> > > +void intel_attach_privacy_screen_property(struct drm_connector *connector);
> > >
> > > #endif /* __INTEL_CONNECTOR_H__ */
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index c2706afc069b..83b8c98049a7 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -426,6 +426,9 @@ struct intel_connector {
> > > struct work_struct modeset_retry_work;
> > >
> > > struct intel_hdcp hdcp;
> > > +
> > > + /* Optional "privacy-screen" property for the connector panel */
> > > + struct drm_property *privacy_screen_property;
> > > };
> > >
> > > struct intel_digital_connector_state {
> > > @@ -433,6 +436,7 @@ struct intel_digital_connector_state {
> > >
> > > enum hdmi_force_audio force_audio;
> > > int broadcast_rgb;
> > > + enum intel_privacy_screen_status privacy_screen_status;
> > > };
> > >
> > > #define to_intel_digital_connector_state(x) container_of(x, struct intel_digital_connector_state, base)
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c
> > > index 4fac408a4299..1963e92404ba 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c
> > > @@ -62,6 +62,7 @@
> > > #include "intel_lspcon.h"
> > > #include "intel_lvds.h"
> > > #include "intel_panel.h"
> > > +#include "intel_privacy_screen.h"
> > > #include "intel_psr.h"
> > > #include "intel_sideband.h"
> > > #include "intel_tc.h"
> > > @@ -6358,6 +6359,10 @@ intel_dp_add_properties(struct intel_dp *intel_dp, struct drm_connector *connect
> > >
> > > /* Lookup the ACPI node corresponding to the connector */
> > > intel_connector_lookup_acpi_node(intel_connector);
> > > +
> > > + /* Check for integrated Privacy screen support */
> > > + if (intel_privacy_screen_present(intel_connector))
> > > + intel_attach_privacy_screen_property(connector);
> > > }
> > > }
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_privacy_screen.c b/drivers/gpu/drm/i915/display/intel_privacy_screen.c
> > > new file mode 100644
> > > index 000000000000..4c422e38c51a
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/i915/display/intel_privacy_screen.c
> > > @@ -0,0 +1,70 @@
> > > +// SPDX-License-Identifier: GPL-2.0-or-later
> >
> > Please read http://mid.mail-archive.com/CAKMK7uH-8+tbKsAoiChsxELEc_77RVVxP2wapHWhqB+0Viifog@mail.gmail.com
>
> OK, I changed it to SPDX-License-Identifier: GPL-2.0 OR MIT
>
>
> >
> > > +/*
> > > + * Intel ACPI privacy screen code
> > > + *
> > > + * Copyright © 2019 Google Inc.
> > > + */
> > > +
> > > +#include <linux/acpi.h>
> > > +
> > > +#include "intel_privacy_screen.h"
> > > +
> > > +#define CONNECTOR_DSM_REVID 1
> > > +
> > > +#define CONNECTOR_DSM_FN_PRIVACY_ENABLE 2
> > > +#define CONNECTOR_DSM_FN_PRIVACY_DISABLE 3
> > > +
> > > +static const guid_t drm_conn_dsm_guid =
> > > + GUID_INIT(0xC7033113, 0x8720, 0x4CEB,
> > > + 0x90, 0x90, 0x9D, 0x52, 0xB3, 0xE5, 0x2D, 0x73);
> > > +
> > > +/* Makes _DSM call to set privacy screen status */
> > > +static void acpi_privacy_screen_call_dsm(acpi_handle conn_handle, u64 func)
> > > +{
> > > + union acpi_object *obj;
> > > +
> > > + obj = acpi_evaluate_dsm(conn_handle, &drm_conn_dsm_guid,
> > > + CONNECTOR_DSM_REVID, func, NULL);
> > > + if (!obj) {
> > > + DRM_DEBUG_DRIVER("failed to evaluate _DSM for fn %llx\n", func);
> > > + return;
> > > + }
> > > +
> > > + ACPI_FREE(obj);
> > > +}
> > > +
> > > +void intel_privacy_screen_set_val(struct intel_connector *intel_connector,
> > > + enum intel_privacy_screen_status val)
> >
> > Just name the parameter connector, not intel_connector. This throughout.
>
> Done.
>
> >
> > > +{
> > > + acpi_handle acpi_handle = intel_connector->acpi_handle;
> > > +
> > > + if (!acpi_handle)
> > > + return;
> > > +
> > > + if (val == PRIVACY_SCREEN_DISABLED)
> > > + acpi_privacy_screen_call_dsm(acpi_handle,
> > > + CONNECTOR_DSM_FN_PRIVACY_DISABLE);
> > > + else if (val == PRIVACY_SCREEN_ENABLED)
> > > + acpi_privacy_screen_call_dsm(acpi_handle,
> > > + CONNECTOR_DSM_FN_PRIVACY_ENABLE);
> >
> > else complain?
> >
>
> Done.
>
> > > +}
> > > +
> > > +bool intel_privacy_screen_present(struct intel_connector *intel_connector)
> > > +{
> > > + acpi_handle handle = intel_connector->acpi_handle;
> > > +
> > > + if (!handle)
> > > + return false;
> > > +
> > > + if (!acpi_check_dsm(handle, &drm_conn_dsm_guid,
> > > + CONNECTOR_DSM_REVID,
> > > + 1 << CONNECTOR_DSM_FN_PRIVACY_ENABLE |
> > > + 1 << CONNECTOR_DSM_FN_PRIVACY_DISABLE)) {
> > > + DRM_WARN("%s: Odd, connector ACPI node but no privacy scrn?\n",
> > > + dev_name(intel_connector->base.dev->dev));
> > > + return false;
> > > + }
> > > + DRM_DEV_INFO(intel_connector->base.dev->dev,
> > > + "supports privacy screen\n");
> > > + return true;
> > > +}
> > > diff --git a/drivers/gpu/drm/i915/display/intel_privacy_screen.h b/drivers/gpu/drm/i915/display/intel_privacy_screen.h
> > > new file mode 100644
> > > index 000000000000..212f73349a00
> > > --- /dev/null
> > > +++ b/drivers/gpu/drm/i915/display/intel_privacy_screen.h
> > > @@ -0,0 +1,25 @@
> > > +/* SPDX-License-Identifier: GPL-2.0-or-later */
> > > +/*
> > > + * Copyright © 2019 Google Inc.
> > > + */
> > > +
> > > +#ifndef __DRM_PRIVACY_SCREEN_H__
> > > +#define __DRM_PRIVACY_SCREEN_H__
> > > +
> > > +#include "intel_display_types.h"
> > > +
> > > +#ifdef CONFIG_ACPI
> > > +bool intel_privacy_screen_present(struct intel_connector *intel_connector);
> > > +void intel_privacy_screen_set_val(struct intel_connector *intel_connector,
> > > + enum intel_privacy_screen_status val);
> > > +#else
> > > +bool intel_privacy_screen_present(struct intel_connector *intel_connector);
> > > +{
> > > + return false;
> > > +}
> > > +void intel_privacy_screen_set_val(struct intel_connector *intel_connector,
> > > + enum intel_privacy_screen_status val)
> > > +{ }
> > > +#endif /* CONFIG_ACPI */
> > > +
> > > +#endif /* __DRM_PRIVACY_SCREEN_H__ */
> > > diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> > > index 469dc512cca3..cf08d5636363 100644
> > > --- a/include/uapi/drm/i915_drm.h
> > > +++ b/include/uapi/drm/i915_drm.h
> > > @@ -2123,6 +2123,20 @@ struct drm_i915_query_engine_info {
> > > struct drm_i915_engine_info engines[];
> > > };
> > >
> > > +/**
> > > + * enum intel_privacy_screen_status - privacy_screen status
> > > + *
> > > + * This enum is used to track and control the state of the integrated privacy
> > > + * screen present on some display panels, via the "privacy-screen" property.
> > > + *
> > > + * @PRIVACY_SCREEN_DISABLED: The privacy-screen on the panel is disabled
> > > + * @PRIVACY_SCREEN_ENABLED: The privacy-screen on the panel is enabled
> > > + **/
> > > +enum intel_privacy_screen_status {
> > > + PRIVACY_SCREEN_DISABLED = 0,
> > > + PRIVACY_SCREEN_ENABLED = 1,
> > > +};
> > > +
> >
> > The drm_property interface UAPI is based on the strings, *not* on the
> > values. Please move the enum out of uapi into the drm code.
>
> Oh, so we don't have to expose this to userspace? Understand, so I
> moved it to intel_display_types.h
>
> Thanks,
>
> Rajat.
>
>
> >
> > BR,
> > jani.
> >
> > > #if defined(__cplusplus)
> > > }
> > > #endif
> >
> > --
> > Jani Nikula, Intel Open Source Graphics Center