On Fri, Jul 18, 2025 at 02:51:16PM +0800, Yongbang Shi wrote:
> From: Baihan Li <libai...@huawei.com>
>
> The debouncing when HPD pulled out still remains sometimes, 200ms still can
> not ensure helper_detect() is correct. Add hibmc_dp_detect_link() in
> detect_ctx(), which is to try dp link training.
I'm not sure if I follow the commit message. Anyway, link training
should be a part of atomic_(pre)_enable, not a detect_ctx.
>
> Fixes: 3c7623fb5bb6 ("drm/hisilicon/hibmc: Enable this hot plug detect of irq
> feature")
> Signed-off-by: Baihan Li <libai...@huawei.com>
> Signed-off-by: Yongbang Shi <shiyongb...@huawei.com>
> ---
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 27 +++++++++++++++----
> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h | 2 ++
> .../gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c | 10 ++++---
> 3 files changed, 30 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> index 8f0daec7d174..2d2fb6e759c3 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> @@ -3,6 +3,7 @@
>
> #include <linux/io.h>
> #include <linux/delay.h>
> +#include <drm/drm_managed.h>
> #include "dp_config.h"
> #include "dp_comm.h"
> #include "dp_reg.h"
> @@ -162,6 +163,8 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
>
> mutex_init(&dp_dev->lock);
>
> + drmm_mutex_init(drm_dev, &dp->link_train_mutex);
> +
> dp->dp_dev = dp_dev;
>
> dp_dev->dev = drm_dev;
> @@ -238,19 +241,33 @@ void hibmc_dp_display_en(struct hibmc_dp *dp, bool
> enable)
> msleep(50);
> }
>
> -int hibmc_dp_mode_set(struct hibmc_dp *dp, struct drm_display_mode *mode)
> +int hibmc_dp_detect_link(struct hibmc_dp *dp)
> {
> struct hibmc_dp_dev *dp_dev = dp->dp_dev;
> - int ret;
> + int ret = 0;
> +
> + mutex_lock(&dp->link_train_mutex);
>
> if (!dp_dev->link.status.channel_equalized) {
> ret = hibmc_dp_link_training(dp_dev);
> - if (ret) {
> + if (ret)
> drm_err(dp->drm_dev, "dp link training failed, ret:
> %d\n", ret);
> - return ret;
> - }
> }
>
> + mutex_unlock(&dp->link_train_mutex);
> +
> + return ret;
> +}
> +
> +int hibmc_dp_mode_set(struct hibmc_dp *dp, struct drm_display_mode *mode)
> +{
> + struct hibmc_dp_dev *dp_dev = dp->dp_dev;
> + int ret;
> +
> + ret = hibmc_dp_detect_link(dp);
> + if (ret)
> + return ret;
> +
> hibmc_dp_display_en(dp, false);
> hibmc_dp_link_cfg(dp_dev, mode);
>
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> index 665f5b166dfb..9b45e88e47e4 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h
> @@ -50,9 +50,11 @@ struct hibmc_dp {
> struct drm_dp_aux aux;
> struct hibmc_dp_cbar_cfg cfg;
> u32 irq_status;
> + struct mutex link_train_mutex; /* link training mutex */
> };
>
> int hibmc_dp_hw_init(struct hibmc_dp *dp);
> +int hibmc_dp_detect_link(struct hibmc_dp *dp);
> int hibmc_dp_mode_set(struct hibmc_dp *dp, struct drm_display_mode *mode);
> void hibmc_dp_display_en(struct hibmc_dp *dp, bool enable);
> void hibmc_dp_set_cbar(struct hibmc_dp *dp, const struct hibmc_dp_cbar_cfg
> *cfg);
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> index d06832e62e96..354e18bb2998 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c
> @@ -34,9 +34,12 @@ static int hibmc_dp_connector_get_modes(struct
> drm_connector *connector)
> static int hibmc_dp_detect(struct drm_connector *connector,
> struct drm_modeset_acquire_ctx *ctx, bool force)
> {
> - mdelay(200);
> + struct hibmc_drm_private *priv = to_hibmc_drm_private(connector->dev);
>
> - return drm_connector_helper_detect_from_ddc(connector, ctx, force);
> + if (!hibmc_dp_detect_link(&priv->dp))
> + return connector_status_connected;
> +
> + return connector_status_disconnected;
> }
>
> static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = {
> @@ -128,8 +131,7 @@ irqreturn_t hibmc_dp_hpd_isr(int irq, void *arg)
> hibmc_dp_reset_link(&priv->dp);
> }
>
> - if (dev->registered)
> - drm_connector_helper_hpd_irq_event(&priv->dp.connector);
> + drm_connector_helper_hpd_irq_event(&priv->dp.connector);
>
> drm_dev_exit(idx);
>
> --
> 2.33.0
>
--
With best wishes
Dmitry
