[PATCH v2] drm/amdgpu: Add support for drm_privacy_screen

Rajat Jain rajatja at google.com
Wed Mar 9 17:53:32 UTC 2022


On Wed, Mar 9, 2022 at 7:06 AM Sean Paul <sean at poorly.run> wrote:
>
> From: Sean Paul <seanpaul at chromium.org>
>
> This patch adds the necessary hooks to make amdgpu aware of privacy
> screens. On devices with privacy screen drivers (such as thinkpad-acpi),
> the amdgpu driver will defer probe until it's ready and then sync the sw
> and hw state on each commit the connector is involved and enabled.
>
> Changes in v2:
> -Tweaked the drm_privacy_screen_get() error check to avoid logging
>  errors when privacy screen is absent (Hans)
>
> Signed-off-by: Sean Paul <seanpaul at chromium.org>
> Link: https://patchwork.freedesktop.org/patch/477640/ #v1
> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c          |  9 +++++++++
>  .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c    |  3 +++
>  .../amd/display/amdgpu_dm/amdgpu_dm_mst_types.c  | 16 +++++++++++++++-
>  3 files changed, 27 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index 2ab675123ae3..e2cfae56c020 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -26,6 +26,7 @@
>  #include <drm/drm_aperture.h>
>  #include <drm/drm_drv.h>
>  #include <drm/drm_gem.h>
> +#include <drm/drm_privacy_screen_consumer.h>
>  #include <drm/drm_vblank.h>
>  #include <drm/drm_managed.h>
>  #include "amdgpu_drv.h"
> @@ -1988,6 +1989,7 @@ static int amdgpu_pci_probe(struct pci_dev *pdev,
>  {
>         struct drm_device *ddev;
>         struct amdgpu_device *adev;
> +       struct drm_privacy_screen *privacy_screen;
>         unsigned long flags = ent->driver_data;
>         int ret, retry = 0, i;
>         bool supports_atomic = false;
> @@ -2063,6 +2065,13 @@ static int amdgpu_pci_probe(struct pci_dev *pdev,
>         size = pci_resource_len(pdev, 0);
>         is_fw_fb = amdgpu_is_fw_framebuffer(base, size);
>
> +       /* If the LCD panel has a privacy screen, defer probe until its ready */
> +       privacy_screen = drm_privacy_screen_get(&pdev->dev, NULL);
> +       if (IS_ERR(privacy_screen) && PTR_ERR(privacy_screen) == -EPROBE_DEFER)
> +               return -EPROBE_DEFER;
> +
> +       drm_privacy_screen_put(privacy_screen);
> +
>         /* Get rid of things like offb */
>         ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev, &amdgpu_kms_driver);
>         if (ret)
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> index e1d3db3fe8de..9e2bb6523add 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> @@ -9781,6 +9781,9 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
>                 if (acrtc) {
>                         new_crtc_state = drm_atomic_get_new_crtc_state(state, &acrtc->base);
>                         old_crtc_state = drm_atomic_get_old_crtc_state(state, &acrtc->base);
> +
> +                       /* Sync the privacy screen state between hw and sw */
> +                       drm_connector_update_privacy_screen(new_con_state);
>                 }
>
>                 /* Skip any modesets/resets */
> diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> index 740435ae3997..594a8002975a 100644
> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_mst_types.c
> @@ -27,6 +27,7 @@
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/dp/drm_dp_mst_helper.h>
>  #include <drm/dp/drm_dp_helper.h>
> +#include <drm/drm_privacy_screen_consumer.h>
>  #include "dm_services.h"
>  #include "amdgpu.h"
>  #include "amdgpu_dm.h"
> @@ -506,6 +507,7 @@ void amdgpu_dm_initialize_dp_connector(struct amdgpu_display_manager *dm,
>                                        struct amdgpu_dm_connector *aconnector,
>                                        int link_index)
>  {
> +       struct drm_device *dev = dm->ddev;
>         struct dc_link_settings max_link_enc_cap = {0};
>
>         aconnector->dm_dp_aux.aux.name =
> @@ -519,8 +521,20 @@ void amdgpu_dm_initialize_dp_connector(struct amdgpu_display_manager *dm,
>         drm_dp_cec_register_connector(&aconnector->dm_dp_aux.aux,
>                                       &aconnector->base);
>
> -       if (aconnector->base.connector_type == DRM_MODE_CONNECTOR_eDP)
> +       if (aconnector->base.connector_type == DRM_MODE_CONNECTOR_eDP) {
> +               struct drm_privacy_screen *privacy_screen)
> +
> +               /* Reference given up in drm_connector_cleanup() */
> +               privacy_screen = drm_privacy_screen_get(dev->dev, NULL);

Can we try to be more specific when looking up for privacy screen, e.g.:

privacy_screen = drm_privacy_screen_get(dev->dev,  "eDP-1");
(and then also making the corresponding change in arch_init_data[] in
drm_privacy_screen_x86.c"

My comment applies to this driver as well as to i915. The reason being
today there is only 1 internal display with privacy screen so we can
just assume that there shall be only 1 privacy-screen and that shall
apply to eDP-1/internal display. But dual display systems are not far
enough out, and perhaps external monitors with inbuilt
privacy-screens?

Essentially the gap today is that today on Chromeos ACPI side, the
device GOOG0010 represents the privacy-screen attached to the internal
display/eDP-1, but there isn't a way to make it clear in the i915 and
now amdgpu code.

Thanks,

Rajat


> +               if (!IS_ERR(privacy_screen)) {
> +                       drm_connector_attach_privacy_screen_provider(&aconnector->base,
> +                                                                    privacy_screen);
> +               } else if (PTR_ERR(privacy_screen) != -ENODEV) {
> +                       drm_err(dev, "Error getting privacy screen, ret=%d\n",
> +                               PTR_ERR(privacy_screen));
> +               }
>                 return;
> +       }
>
>         dc_link_dp_get_max_link_enc_cap(aconnector->dc_link, &max_link_enc_cap);
>         aconnector->mst_mgr.cbs = &dm_mst_cbs;
> --
> Sean Paul, Software Engineer, Google / Chromium OS
>


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