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Message-ID: <a5d6bcb4-3963-cadd-e2b7-81cec20c1464@linaro.org>
Date: Fri, 15 Apr 2022 00:32:13 +0300
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Kuogee Hsieh <quic_khsieh@...cinc.com>, robdclark@...il.com,
sean@...rly.run, swboyd@...omium.org, vkoul@...nel.org,
daniel@...ll.ch, airlied@...ux.ie, agross@...nel.org,
bjorn.andersson@...aro.org
Cc: quic_abhinavk@...cinc.com, quic_aravindh@...cinc.com,
quic_sbillaka@...cinc.com, freedreno@...ts.freedesktop.org,
dri-devel@...ts.freedesktop.org, linux-arm-msm@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4] drm/msm/dp: stop event kernel thread when DP unbind
On 15/04/2022 00:26, Kuogee Hsieh wrote:
> Current DP driver implementation, event thread is kept running
> after DP display is unbind. This patch fix this problem by disabling
> DP irq and stop event thread to exit gracefully at dp_display_unbind().
>
> Changes in v2:
> -- start event thread at dp_display_bind()
>
> Changes in v3:
> -- disable all HDP interrupts at unbind
> -- replace dp_hpd_event_setup() with dp_hpd_event_thread_start()
> -- replace dp_hpd_event_stop() with dp_hpd_event_thread_stop()
> -- move init_waitqueue_head(&dp->event_q) to probe()
> -- move spin_lock_init(&dp->event_lock) to probe()
>
> Changes in v4:
> -- relocate both dp_display_bind() and dp_display_unbind() to bottom of file
Ugh, no. I think Stephen asked to do it in the followup (= additional)
patch. Doing it in the same patch squashes unrelated changes and makes
review harder. The previous one was nearly ideal.
>
> Fixes: e91e3065a806 ("drm/msm/dp: Add DP compliance tests on Snapdragon Chipsets")
> Signed-off-by: Kuogee Hsieh <quic_khsieh@...cinc.com>
> Reported-by: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
> ---
> drivers/gpu/drm/msm/dp/dp_display.c | 345 +++++++++++++++++++-----------------
> 1 file changed, 182 insertions(+), 163 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dp/dp_display.c b/drivers/gpu/drm/msm/dp/dp_display.c
> index 01453db..198df6b 100644
> --- a/drivers/gpu/drm/msm/dp/dp_display.c
> +++ b/drivers/gpu/drm/msm/dp/dp_display.c
> @@ -113,6 +113,7 @@ struct dp_display_private {
> u32 hpd_state;
> u32 event_pndx;
> u32 event_gndx;
> + struct task_struct *ev_tsk;
> struct dp_event event_list[DP_EVENT_Q_MAX];
> spinlock_t event_lock;
>
> @@ -230,65 +231,6 @@ void dp_display_signal_audio_complete(struct msm_dp *dp_display)
> complete_all(&dp->audio_comp);
> }
>
> -static int dp_display_bind(struct device *dev, struct device *master,
> - void *data)
> -{
> - int rc = 0;
> - struct dp_display_private *dp = dev_get_dp_display_private(dev);
> - struct msm_drm_private *priv;
> - struct drm_device *drm;
> -
> - drm = dev_get_drvdata(master);
> -
> - dp->dp_display.drm_dev = drm;
> - priv = drm->dev_private;
> - priv->dp[dp->id] = &dp->dp_display;
> -
> - rc = dp->parser->parse(dp->parser, dp->dp_display.connector_type);
> - if (rc) {
> - DRM_ERROR("device tree parsing failed\n");
> - goto end;
> - }
> -
> - dp->dp_display.panel_bridge = dp->parser->panel_bridge;
> -
> - dp->aux->drm_dev = drm;
> - rc = dp_aux_register(dp->aux);
> - if (rc) {
> - DRM_ERROR("DRM DP AUX register failed\n");
> - goto end;
> - }
> -
> - rc = dp_power_client_init(dp->power);
> - if (rc) {
> - DRM_ERROR("Power client create failed\n");
> - goto end;
> - }
> -
> - rc = dp_register_audio_driver(dev, dp->audio);
> - if (rc)
> - DRM_ERROR("Audio registration Dp failed\n");
> -
> -end:
> - return rc;
> -}
> -
> -static void dp_display_unbind(struct device *dev, struct device *master,
> - void *data)
> -{
> - struct dp_display_private *dp = dev_get_dp_display_private(dev);
> - struct drm_device *drm = dev_get_drvdata(master);
> - struct msm_drm_private *priv = drm->dev_private;
> -
> - dp_power_client_deinit(dp->power);
> - dp_aux_unregister(dp->aux);
> - priv->dp[dp->id] = NULL;
> -}
> -
> -static const struct component_ops dp_display_comp_ops = {
> - .bind = dp_display_bind,
> - .unbind = dp_display_unbind,
> -};
>
> static bool dp_display_is_ds_bridge(struct dp_panel *panel)
> {
> @@ -1054,7 +996,7 @@ static int hpd_event_thread(void *data)
>
> dp_priv = (struct dp_display_private *)data;
>
> - while (1) {
> + while (!kthread_should_stop()) {
> if (timeout_mode) {
> wait_event_timeout(dp_priv->event_q,
> (dp_priv->event_pndx == dp_priv->event_gndx),
> @@ -1132,14 +1074,6 @@ static int hpd_event_thread(void *data)
> return 0;
> }
>
> -static void dp_hpd_event_setup(struct dp_display_private *dp_priv)
> -{
> - init_waitqueue_head(&dp_priv->event_q);
> - spin_lock_init(&dp_priv->event_lock);
> -
> - kthread_run(hpd_event_thread, dp_priv, "dp_hpd_handler");
> -}
> -
> static irqreturn_t dp_display_irq_handler(int irq, void *dev_id)
> {
> struct dp_display_private *dp = dev_id;
> @@ -1237,65 +1171,6 @@ static const struct msm_dp_desc *dp_display_get_desc(struct platform_device *pde
> return NULL;
> }
>
> -static int dp_display_probe(struct platform_device *pdev)
> -{
> - int rc = 0;
> - struct dp_display_private *dp;
> - const struct msm_dp_desc *desc;
> -
> - if (!pdev || !pdev->dev.of_node) {
> - DRM_ERROR("pdev not found\n");
> - return -ENODEV;
> - }
> -
> - dp = devm_kzalloc(&pdev->dev, sizeof(*dp), GFP_KERNEL);
> - if (!dp)
> - return -ENOMEM;
> -
> - desc = dp_display_get_desc(pdev, &dp->id);
> - if (!desc)
> - return -EINVAL;
> -
> - dp->pdev = pdev;
> - dp->name = "drm_dp";
> - dp->dp_display.connector_type = desc->connector_type;
> -
> - rc = dp_init_sub_modules(dp);
> - if (rc) {
> - DRM_ERROR("init sub module failed\n");
> - return -EPROBE_DEFER;
> - }
> -
> - mutex_init(&dp->event_mutex);
> -
> - /* Store DP audio handle inside DP display */
> - dp->dp_display.dp_audio = dp->audio;
> -
> - init_completion(&dp->audio_comp);
> -
> - platform_set_drvdata(pdev, &dp->dp_display);
> -
> - rc = component_add(&pdev->dev, &dp_display_comp_ops);
> - if (rc) {
> - DRM_ERROR("component add failed, rc=%d\n", rc);
> - dp_display_deinit_sub_modules(dp);
> - }
> -
> - return rc;
> -}
> -
> -static int dp_display_remove(struct platform_device *pdev)
> -{
> - struct dp_display_private *dp = dev_get_dp_display_private(&pdev->dev);
> -
> - dp_display_deinit_sub_modules(dp);
> -
> - component_del(&pdev->dev, &dp_display_comp_ops);
> - platform_set_drvdata(pdev, NULL);
> -
> - return 0;
> -}
> -
> static int dp_pm_resume(struct device *dev)
> {
> struct platform_device *pdev = to_platform_device(dev);
> @@ -1398,40 +1273,6 @@ static void dp_pm_complete(struct device *dev)
>
> }
>
> -static const struct dev_pm_ops dp_pm_ops = {
> - .suspend = dp_pm_suspend,
> - .resume = dp_pm_resume,
> - .prepare = dp_pm_prepare,
> - .complete = dp_pm_complete,
> -};
> -
> -static struct platform_driver dp_display_driver = {
> - .probe = dp_display_probe,
> - .remove = dp_display_remove,
> - .driver = {
> - .name = "msm-dp-display",
> - .of_match_table = dp_dt_match,
> - .suppress_bind_attrs = true,
> - .pm = &dp_pm_ops,
> - },
> -};
> -
> -int __init msm_dp_register(void)
> -{
> - int ret;
> -
> - ret = platform_driver_register(&dp_display_driver);
> - if (ret)
> - DRM_ERROR("Dp display driver register failed");
> -
> - return ret;
> -}
> -
> -void __exit msm_dp_unregister(void)
> -{
> - platform_driver_unregister(&dp_display_driver);
> -}
> -
> void msm_dp_irq_postinstall(struct msm_dp *dp_display)
> {
> struct dp_display_private *dp;
> @@ -1441,8 +1282,6 @@ void msm_dp_irq_postinstall(struct msm_dp *dp_display)
>
> dp = container_of(dp_display, struct dp_display_private, dp_display);
>
> - dp_hpd_event_setup(dp);
> -
> dp_add_event(dp, EV_HPD_INIT_SETUP, 0, 100);
> }
>
> @@ -1640,3 +1479,183 @@ void msm_dp_display_mode_set(struct msm_dp *dp, struct drm_encoder *encoder,
> dp_display->dp_mode.h_active_low =
> !!(dp_display->dp_mode.drm_mode.flags & DRM_MODE_FLAG_NHSYNC);
> }
> +
> +static int dp_hpd_event_thread_start(struct dp_display_private *dp_priv)
> +{
> + dp_priv->ev_tsk = kthread_run(hpd_event_thread, dp_priv, "dp_hpd_handler");
> + if (IS_ERR(dp_priv->ev_tsk)) {
> + DRM_ERROR("failed to create DP event thread\n");
> + return PTR_ERR(dp_priv->ev_tsk);
> + }
> +
> + return 0;
> +}
> +
> +static void dp_hpd_event_thread_stop(struct dp_display_private *dp_priv)
> +{
> + kthread_stop(dp_priv->ev_tsk);
> +
> + /* reset event q to empty */
> + dp_priv->event_gndx = 0;
> + dp_priv->event_pndx = 0;
> +}
> +
> +static int dp_display_bind(struct device *dev, struct device *master,
> + void *data)
> +{
> + int rc = 0;
> + struct dp_display_private *dp = dev_get_dp_display_private(dev);
> + struct msm_drm_private *priv;
> + struct drm_device *drm;
> +
> + drm = dev_get_drvdata(master);
> +
> + dp->dp_display.drm_dev = drm;
> + priv = drm->dev_private;
> + priv->dp[dp->id] = &dp->dp_display;
> +
> + rc = dp->parser->parse(dp->parser, dp->dp_display.connector_type);
> + if (rc) {
> + DRM_ERROR("device tree parsing failed\n");
> + goto end;
> + }
> +
> + dp->dp_display.panel_bridge = dp->parser->panel_bridge;
> +
> + dp->aux->drm_dev = drm;
> + rc = dp_aux_register(dp->aux);
> + if (rc) {
> + DRM_ERROR("DRM DP AUX register failed\n");
> + goto end;
> + }
> +
> + rc = dp_power_client_init(dp->power);
> + if (rc) {
> + DRM_ERROR("Power client create failed\n");
> + goto end;
> + }
> +
> + rc = dp_register_audio_driver(dev, dp->audio);
> + if (rc)
> + DRM_ERROR("Audio registration Dp failed\n");
> +
> + rc = dp_hpd_event_thread_start(dp);
> +end:
> + return rc;
> +}
> +
> +static void dp_display_unbind(struct device *dev, struct device *master,
> + void *data)
> +{
> + struct dp_display_private *dp = dev_get_dp_display_private(dev);
> + struct drm_device *drm = dev_get_drvdata(master);
> + struct msm_drm_private *priv = drm->dev_private;
> +
> + /* disable all HPD interrupts */
> + dp_catalog_hpd_config_intr(dp->catalog, DP_DP_HPD_INT_MASK, false);
> + dp_hpd_event_thread_stop(dp);
> + dp_power_client_deinit(dp->power);
> + dp_aux_unregister(dp->aux);
> + priv->dp[dp->id] = NULL;
> +}
> +
> +static const struct component_ops dp_display_comp_ops = {
> + .bind = dp_display_bind,
> + .unbind = dp_display_unbind,
> +};
> +
> +static int dp_display_probe(struct platform_device *pdev)
> +{
> + int rc = 0;
> + struct dp_display_private *dp;
> + const struct msm_dp_desc *desc;
> +
> + if (!pdev || !pdev->dev.of_node) {
> + DRM_ERROR("pdev not found\n");
> + return -ENODEV;
> + }
> +
> + dp = devm_kzalloc(&pdev->dev, sizeof(*dp), GFP_KERNEL);
> + if (!dp)
> + return -ENOMEM;
> +
> + desc = dp_display_get_desc(pdev, &dp->id);
> + if (!desc)
> + return -EINVAL;
> +
> + dp->pdev = pdev;
> + dp->name = "drm_dp";
> + dp->dp_display.connector_type = desc->connector_type;
> +
> + rc = dp_init_sub_modules(dp);
> + if (rc) {
> + DRM_ERROR("init sub module failed\n");
> + return -EPROBE_DEFER;
> + }
> +
> + /* setup event q */
> + mutex_init(&dp->event_mutex);
> + init_waitqueue_head(&dp->event_q);
> + spin_lock_init(&dp->event_lock);
> +
> + /* Store DP audio handle inside DP display */
> + dp->dp_display.dp_audio = dp->audio;
> +
> + init_completion(&dp->audio_comp);
> +
> + platform_set_drvdata(pdev, &dp->dp_display);
> +
> + rc = component_add(&pdev->dev, &dp_display_comp_ops);
> + if (rc) {
> + DRM_ERROR("component add failed, rc=%d\n", rc);
> + dp_display_deinit_sub_modules(dp);
> + }
> +
> + return rc;
> +}
> +
> +static int dp_display_remove(struct platform_device *pdev)
> +{
> + struct dp_display_private *dp = dev_get_dp_display_private(&pdev->dev);
> +
> + dp_display_deinit_sub_modules(dp);
> +
> + component_del(&pdev->dev, &dp_display_comp_ops);
> + platform_set_drvdata(pdev, NULL);
> +
> + return 0;
> +}
> +
> +static const struct dev_pm_ops dp_pm_ops = {
> + .suspend = dp_pm_suspend,
> + .resume = dp_pm_resume,
> + .prepare = dp_pm_prepare,
> + .complete = dp_pm_complete,
> +};
> +
> +static struct platform_driver dp_display_driver = {
> + .probe = dp_display_probe,
> + .remove = dp_display_remove,
> + .driver = {
> + .name = "msm-dp-display",
> + .of_match_table = dp_dt_match,
> + .suppress_bind_attrs = true,
> + .pm = &dp_pm_ops,
> + },
> +};
> +
> +int __init msm_dp_register(void)
> +{
> + int ret;
> +
> + ret = platform_driver_register(&dp_display_driver);
> + if (ret)
> + DRM_ERROR("Dp display driver register failed");
> +
> + return ret;
> +}
> +
> +void __exit msm_dp_unregister(void)
> +{
> + platform_driver_unregister(&dp_display_driver);
> +}
--
With best wishes
Dmitry
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