Re: [PATCH v2] drm/amdgpu: Retry DDC probing on DVI on failure if we got an HPD interrupt

From: Alex Deucher
Date: Tue Jan 03 2023 - 15:36:45 EST


On Fri, Dec 23, 2022 at 9:23 AM xurui <xurui@xxxxxxxxxx> wrote:
>
> HPD signals on DVI ports can be fired off before the pins required for
> DDC probing actually make contact, due to the pins for HPD making
> contact first. This results in a HPD signal being asserted but DDC
> probing failing, resulting in hotplugging occasionally failing.
>
> Rescheduling the hotplug work for a second when we run into an HPD
> signal with a failing DDC probe usually gives enough time for the rest
> of the connector's pins to make contact, and fixes this issue.
>
> Signed-off-by: xurui <xurui@xxxxxxxxxx>
> Reported-by: kernel test robot<lkp@xxxxxxxxx>

Applied. Thanks!

Alex


> ---
> V1 -> V2: Fixed a compilation error
>
> drivers/gpu/drm/amd/amdgpu/amdgpu.h | 2 +-
> .../gpu/drm/amd/amdgpu/amdgpu_connectors.c | 22 ++++++++++++++++++-
> drivers/gpu/drm/amd/amdgpu/amdgpu_display.c | 2 +-
> drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h | 1 +
> drivers/gpu/drm/amd/amdgpu/dce_v10_0.c | 6 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v11_0.c | 6 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v6_0.c | 6 ++---
> drivers/gpu/drm/amd/amdgpu/dce_v8_0.c | 6 ++---
> 8 files changed, 36 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index 6b74df446694..b1d901fe578e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -870,7 +870,7 @@ struct amdgpu_device {
> struct amdgpu_vkms_output *amdgpu_vkms_output;
> struct amdgpu_mode_info mode_info;
> /* For pre-DCE11. DCE11 and later are in "struct amdgpu_device->dm" */
> - struct work_struct hotplug_work;
> + struct delayed_work hotplug_work;
> struct amdgpu_irq_src crtc_irq;
> struct amdgpu_irq_src vline0_irq;
> struct amdgpu_irq_src vupdate_irq;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> index 2ebbc6382a06..d2abd334b1b5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_connectors.c
> @@ -996,13 +996,33 @@ amdgpu_connector_dvi_detect(struct drm_connector *connector, bool force)
> }
> }
>
> + if (amdgpu_connector->detected_hpd_without_ddc) {
> + force = true;
> + amdgpu_connector->detected_hpd_without_ddc = false;
> + }
> +
> if (!force && amdgpu_connector_check_hpd_status_unchanged(connector)) {
> ret = connector->status;
> goto exit;
> }
>
> - if (amdgpu_connector->ddc_bus)
> + if (amdgpu_connector->ddc_bus) {
> dret = amdgpu_display_ddc_probe(amdgpu_connector, false);
> +
> + /* Sometimes the pins required for the DDC probe on DVI
> + * connectors don't make contact at the same time that the ones
> + * for HPD do. If the DDC probe fails even though we had an HPD
> + * signal, try again later
> + */
> + if (!dret && !force &&
> + amdgpu_display_hpd_sense(adev, amdgpu_connector->hpd.hpd)) {
> + DRM_DEBUG_KMS("hpd detected without ddc, retrying in 1 second\n");
> + amdgpu_connector->detected_hpd_without_ddc = true;
> + schedule_delayed_work(&adev->hotplug_work,
> + msecs_to_jiffies(1000));
> + goto exit;
> + }
> + }
> if (dret) {
> amdgpu_connector->detected_by_load = false;
> amdgpu_connector_free_edid(connector);
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> index b22471b3bd63..a876648e3d7a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
> @@ -63,7 +63,7 @@
> void amdgpu_display_hotplug_work_func(struct work_struct *work)
> {
> struct amdgpu_device *adev = container_of(work, struct amdgpu_device,
> - hotplug_work);
> + hotplug_work.work);
> struct drm_device *dev = adev_to_drm(adev);
> struct drm_mode_config *mode_config = &dev->mode_config;
> struct drm_connector *connector;
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> index 8a39300b1a84..93c73faa5714 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mode.h
> @@ -534,6 +534,7 @@ struct amdgpu_connector {
> void *con_priv;
> bool dac_load_detect;
> bool detected_by_load; /* if the connection status was determined by load */
> + bool detected_hpd_without_ddc; /* if an HPD signal was detected on DVI, but ddc probing failed */
> uint16_t connector_object_id;
> struct amdgpu_hpd hpd;
> struct amdgpu_router router;
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> index 248f1a4e915f..e85e57933cc4 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> @@ -2837,7 +2837,7 @@ static int dce_v10_0_sw_init(void *handle)
> if (r)
> return r;
>
> - INIT_WORK(&adev->hotplug_work,
> + INIT_DELAYED_WORK(&adev->hotplug_work,
> amdgpu_display_hotplug_work_func);
>
> drm_kms_helper_poll_init(adev_to_drm(adev));
> @@ -2902,7 +2902,7 @@ static int dce_v10_0_hw_fini(void *handle)
>
> dce_v10_0_pageflip_interrupt_fini(adev);
>
> - flush_work(&adev->hotplug_work);
> + flush_delayed_work(&adev->hotplug_work);
>
> return 0;
> }
> @@ -3302,7 +3302,7 @@ static int dce_v10_0_hpd_irq(struct amdgpu_device *adev,
>
> if (disp_int & mask) {
> dce_v10_0_hpd_int_ack(adev, hpd);
> - schedule_work(&adev->hotplug_work);
> + schedule_delayed_work(&adev->hotplug_work, 0);
> DRM_DEBUG("IH: HPD%d\n", hpd + 1);
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> index cd9c19060d89..6b406bb7f3f3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> @@ -2956,7 +2956,7 @@ static int dce_v11_0_sw_init(void *handle)
> if (r)
> return r;
>
> - INIT_WORK(&adev->hotplug_work,
> + INIT_DELAYED_WORK(&adev->hotplug_work,
> amdgpu_display_hotplug_work_func);
>
> drm_kms_helper_poll_init(adev_to_drm(adev));
> @@ -3032,7 +3032,7 @@ static int dce_v11_0_hw_fini(void *handle)
>
> dce_v11_0_pageflip_interrupt_fini(adev);
>
> - flush_work(&adev->hotplug_work);
> + flush_delayed_work(&adev->hotplug_work);
>
> return 0;
> }
> @@ -3426,7 +3426,7 @@ static int dce_v11_0_hpd_irq(struct amdgpu_device *adev,
>
> if (disp_int & mask) {
> dce_v11_0_hpd_int_ack(adev, hpd);
> - schedule_work(&adev->hotplug_work);
> + schedule_delayed_work(&adev->hotplug_work, 0);
> DRM_DEBUG("IH: HPD%d\n", hpd + 1);
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> index 76323deecc58..2aa21eec0e06 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> @@ -2715,7 +2715,7 @@ static int dce_v6_0_sw_init(void *handle)
> return r;
>
> /* Pre-DCE11 */
> - INIT_WORK(&adev->hotplug_work,
> + INIT_DELAYED_WORK(&adev->hotplug_work,
> amdgpu_display_hotplug_work_func);
>
> drm_kms_helper_poll_init(adev_to_drm(adev));
> @@ -2776,7 +2776,7 @@ static int dce_v6_0_hw_fini(void *handle)
>
> dce_v6_0_pageflip_interrupt_fini(adev);
>
> - flush_work(&adev->hotplug_work);
> + flush_delayed_work(&adev->hotplug_work);
>
> return 0;
> }
> @@ -3103,7 +3103,7 @@ static int dce_v6_0_hpd_irq(struct amdgpu_device *adev,
> tmp = RREG32(mmDC_HPD1_INT_CONTROL + hpd_offsets[hpd]);
> tmp |= DC_HPD1_INT_CONTROL__DC_HPD1_INT_ACK_MASK;
> WREG32(mmDC_HPD1_INT_CONTROL + hpd_offsets[hpd], tmp);
> - schedule_work(&adev->hotplug_work);
> + schedule_delayed_work(&adev->hotplug_work, 0);
> DRM_DEBUG("IH: HPD%d\n", hpd + 1);
> }
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> index 01cf3ab111cb..9da338889d36 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> @@ -2739,7 +2739,7 @@ static int dce_v8_0_sw_init(void *handle)
> return r;
>
> /* Pre-DCE11 */
> - INIT_WORK(&adev->hotplug_work,
> + INIT_DELAYED_WORK(&adev->hotplug_work,
> amdgpu_display_hotplug_work_func);
>
> drm_kms_helper_poll_init(adev_to_drm(adev));
> @@ -2802,7 +2802,7 @@ static int dce_v8_0_hw_fini(void *handle)
>
> dce_v8_0_pageflip_interrupt_fini(adev);
>
> - flush_work(&adev->hotplug_work);
> + flush_delayed_work(&adev->hotplug_work);
>
> return 0;
> }
> @@ -3195,7 +3195,7 @@ static int dce_v8_0_hpd_irq(struct amdgpu_device *adev,
> tmp = RREG32(mmDC_HPD1_INT_CONTROL + hpd_offsets[hpd]);
> tmp |= DC_HPD1_INT_CONTROL__DC_HPD1_INT_ACK_MASK;
> WREG32(mmDC_HPD1_INT_CONTROL + hpd_offsets[hpd], tmp);
> - schedule_work(&adev->hotplug_work);
> + schedule_delayed_work(&adev->hotplug_work, 0);
> DRM_DEBUG("IH: HPD%d\n", hpd + 1);
> }
>
> --
> 2.25.1
>