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Message-Id: <20230713090152.140060-11-angelogioacchino.delregno@collabora.com>
Date: Thu, 13 Jul 2023 11:01:52 +0200
From: AngeloGioacchino Del Regno
<angelogioacchino.delregno@...labora.com>
To: chunkuang.hu@...nel.org
Cc: p.zabel@...gutronix.de, airlied@...il.com, daniel@...ll.ch,
matthias.bgg@...il.com, angelogioacchino.delregno@...labora.com,
dri-devel@...ts.freedesktop.org,
linux-mediatek@...ts.infradead.org, linux-kernel@...r.kernel.org,
linux-arm-kernel@...ts.infradead.org, kernel@...labora.com,
wenst@...omium.org, nfraprado@...labora.com
Subject: [PATCH v5 10/10] drm/mediatek: dp: Don't register HPD interrupt handler for eDP case
The interrupt handler for HPD is useful only if a display is actually
supposed to be hotpluggable, as that manages the machinery to perform
cable (un)plug detection, debouncing and setup for re-training.
Since eDP panels are not supposed to be hotpluggable we can avoid
using the HPD interrupts altogether and rely on HPD polling only
for the suspend/resume case, saving us some spinlocking action and
the overhead of interrupts firing at every suspend/resume cycle,
achieving a faster (even if just slightly) display resume.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@...labora.com>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 81 ++++++++++++++++++-------------
1 file changed, 46 insertions(+), 35 deletions(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index a00bf6693b28..14eeb4a74191 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -2175,9 +2175,11 @@ static int mtk_dp_bridge_attach(struct drm_bridge *bridge,
mtk_dp->drm_dev = bridge->dev;
- irq_clear_status_flags(mtk_dp->irq, IRQ_NOAUTOEN);
- enable_irq(mtk_dp->irq);
- mtk_dp_hwirq_enable(mtk_dp, true);
+ if (mtk_dp->bridge.type != DRM_MODE_CONNECTOR_eDP) {
+ irq_clear_status_flags(mtk_dp->irq, IRQ_NOAUTOEN);
+ enable_irq(mtk_dp->irq);
+ mtk_dp_hwirq_enable(mtk_dp, true);
+ }
return 0;
@@ -2192,8 +2194,10 @@ static void mtk_dp_bridge_detach(struct drm_bridge *bridge)
{
struct mtk_dp *mtk_dp = mtk_dp_from_bridge(bridge);
- mtk_dp_hwirq_enable(mtk_dp, false);
- disable_irq(mtk_dp->irq);
+ if (mtk_dp->bridge.type != DRM_MODE_CONNECTOR_eDP) {
+ mtk_dp_hwirq_enable(mtk_dp, false);
+ disable_irq(mtk_dp->irq);
+ }
mtk_dp->drm_dev = NULL;
mtk_dp_poweroff(mtk_dp);
drm_dp_aux_unregister(&mtk_dp->aux);
@@ -2567,40 +2571,44 @@ static int mtk_dp_probe(struct platform_device *pdev)
mtk_dp->dev = dev;
mtk_dp->data = (struct mtk_dp_data *)of_device_get_match_data(dev);
- mtk_dp->irq = platform_get_irq(pdev, 0);
- if (mtk_dp->irq < 0)
- return dev_err_probe(dev, mtk_dp->irq,
- "failed to request dp irq resource\n");
-
- mtk_dp->next_bridge = devm_drm_of_get_bridge(dev, dev->of_node, 1, 0);
- if (IS_ERR(mtk_dp->next_bridge) &&
- PTR_ERR(mtk_dp->next_bridge) == -ENODEV)
- mtk_dp->next_bridge = NULL;
- else if (IS_ERR(mtk_dp->next_bridge))
- return dev_err_probe(dev, PTR_ERR(mtk_dp->next_bridge),
- "Failed to get bridge\n");
-
ret = mtk_dp_dt_parse(mtk_dp, pdev);
if (ret)
return dev_err_probe(dev, ret, "Failed to parse dt\n");
+ /*
+ * Request the interrupt and install service routine only if we are
+ * on full DisplayPort.
+ * For eDP, polling the HPD instead is more convenient because we
+ * don't expect any (un)plug events during runtime, hence we can
+ * avoid some locking.
+ */
+ if (mtk_dp->data->bridge_type != DRM_MODE_CONNECTOR_eDP) {
+ mtk_dp->irq = platform_get_irq(pdev, 0);
+ if (mtk_dp->irq < 0)
+ return dev_err_probe(dev, mtk_dp->irq,
+ "failed to request dp irq resource\n");
+
+ spin_lock_init(&mtk_dp->irq_thread_lock);
+
+ irq_set_status_flags(mtk_dp->irq, IRQ_NOAUTOEN);
+ ret = devm_request_threaded_irq(dev, mtk_dp->irq, mtk_dp_hpd_event,
+ mtk_dp_hpd_event_thread,
+ IRQ_TYPE_LEVEL_HIGH, dev_name(dev),
+ mtk_dp);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "failed to request mediatek dptx irq\n");
+
+ mtk_dp->need_debounce = true;
+ timer_setup(&mtk_dp->debounce_timer, mtk_dp_debounce_timer, 0);
+ }
+
mtk_dp->aux.name = "aux_mtk_dp";
mtk_dp->aux.dev = dev;
mtk_dp->aux.transfer = mtk_dp_aux_transfer;
mtk_dp->aux.wait_hpd_asserted = mtk_dp_wait_hpd_asserted;
drm_dp_aux_init(&mtk_dp->aux);
- spin_lock_init(&mtk_dp->irq_thread_lock);
-
- irq_set_status_flags(mtk_dp->irq, IRQ_NOAUTOEN);
- ret = devm_request_threaded_irq(dev, mtk_dp->irq, mtk_dp_hpd_event,
- mtk_dp_hpd_event_thread,
- IRQ_TYPE_LEVEL_HIGH, dev_name(dev),
- mtk_dp);
- if (ret)
- return dev_err_probe(dev, ret,
- "failed to request mediatek dptx irq\n");
-
platform_set_drvdata(pdev, mtk_dp);
if (mtk_dp->data->audio_supported) {
@@ -2628,9 +2636,6 @@ static int mtk_dp_probe(struct platform_device *pdev)
devm_drm_bridge_add(dev, &mtk_dp->bridge);
- mtk_dp->need_debounce = true;
- timer_setup(&mtk_dp->debounce_timer, mtk_dp_debounce_timer, 0);
-
if (mtk_dp->bridge.type == DRM_MODE_CONNECTOR_eDP) {
/*
* Set the data lanes to idle in case the bootloader didn't
@@ -2641,6 +2646,9 @@ static int mtk_dp_probe(struct platform_device *pdev)
mtk_dp_initialize_aux_settings(mtk_dp);
mtk_dp_power_enable(mtk_dp);
+ /* Disable HW interrupts: we don't need any for eDP */
+ mtk_dp_hwirq_enable(mtk_dp, false);
+
/*
* Power on the AUX to allow reading the EDID from aux-bus:
* please note that it is necessary to call power off in the
@@ -2680,7 +2688,8 @@ static int mtk_dp_remove(struct platform_device *pdev)
pm_runtime_put(&pdev->dev);
pm_runtime_disable(&pdev->dev);
- del_timer_sync(&mtk_dp->debounce_timer);
+ if (mtk_dp->data->bridge_type != DRM_MODE_CONNECTOR_eDP)
+ del_timer_sync(&mtk_dp->debounce_timer);
drm_bridge_remove(&mtk_dp->bridge);
platform_device_unregister(mtk_dp->phy_dev);
if (mtk_dp->audio_pdev)
@@ -2695,7 +2704,8 @@ static int mtk_dp_suspend(struct device *dev)
struct mtk_dp *mtk_dp = dev_get_drvdata(dev);
mtk_dp_power_disable(mtk_dp);
- mtk_dp_hwirq_enable(mtk_dp, false);
+ if (mtk_dp->bridge.type != DRM_MODE_CONNECTOR_eDP)
+ mtk_dp_hwirq_enable(mtk_dp, false);
pm_runtime_put_sync(dev);
return 0;
@@ -2707,7 +2717,8 @@ static int mtk_dp_resume(struct device *dev)
pm_runtime_get_sync(dev);
mtk_dp_init_port(mtk_dp);
- mtk_dp_hwirq_enable(mtk_dp, true);
+ if (mtk_dp->bridge.type != DRM_MODE_CONNECTOR_eDP)
+ mtk_dp_hwirq_enable(mtk_dp, true);
mtk_dp_power_enable(mtk_dp);
return 0;
--
2.40.1
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