From: Guillaume Ranquet <granquet@baylibre.com>
To: Chun-Kuang Hu <chunkuang.hu@kernel.org>,
Philipp Zabel <p.zabel@pengutronix.de>,
David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
Matthias Brugger <matthias.bgg@gmail.com>,
Chunfeng Yun <chunfeng.yun@mediatek.com>,
Kishon Vijay Abraham I <kishon@ti.com>,
Vinod Koul <vkoul@kernel.org>, Helge Deller <deller@gmx.de>,
CK Hu <ck.hu@mediatek.com>, Jitao shi <jitao.shi@mediatek.com>
Cc: Rex-BC Chen <rex-bc.chen@mediatek.com>,
dri-devel@lists.freedesktop.org,
linux-mediatek@lists.infradead.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-phy@lists.infradead.org, linux-fbdev@vger.kernel.org
Subject: [PATCH v10 20/21] drm/mediatek: add hpd debounce
Date: Mon, 23 May 2022 12:47:53 +0200 [thread overview]
Message-ID: <20220523104758.29531-21-granquet@baylibre.com> (raw)
In-Reply-To: <20220523104758.29531-1-granquet@baylibre.com>
From: Jitao Shi <jitao.shi@mediatek.com>
From the DP spec 1.4a chapter 3.3, upstream devices should implement
HPD signal de-bouncing on an external connection.
A period of 100ms should be used to detect an HPD connect event.
To cover these cases, HPD de-bounce should be implemented only after
HPD low has been detected for at least 100ms.
Therefore,
1. If HPD is low (which means plugging out) for longer than 100ms:
we need to do de-bouncing (which means we need to wait for 100ms).
2. If HPD low is for less than 100ms:
we don't need to care about the de-bouncing.
In this patch, we start a 100ms timer and use a need_debounce boolean
to implement the feature.
Two cases when HPD is high:
1. If the timer is expired (>100ms):
- need_debounce is true.
- When HPD high (plugging event comes), need_debounce will be true
and then we need to do de-bouncing (wait for 100ms).
2. If the timer is not expired (<100ms):
- need_debounce is false.
- When HPD high (plugging event comes), need_debounce will be false
and no need to do de-bouncing.
HPD_______ __________________
| |<- 100ms ->
|____________|
<- 100ms ->
Without HPD de-bouncing, USB-C to HDMI Adapaters will not be detected.
The change has been successfully tested with the following devices:
- Dell Adapter - USB-C to HDMI
- Acer 1in1 HDMI dongle
- Ugreen 1in1 HDMI dongle
- innowatt HDMI + USB3 hub
- Acer 2in1 HDMI dongle
- Apple 3in1 HDMI dongle (A2119)
- J5Create 3in1 HDMI dongle (JAC379)
Tested-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Reviewed-by: Rex-BC Chen <rex-bc.chen@mediatek.com>
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Guillaume Ranquet <granquet@baylibre.com>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 4789853ec5ff..c056bc3ca9f6 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -154,6 +154,8 @@ struct mtk_dp {
struct mutex dp_lock;
struct drm_connector *conn;
+ bool need_debounce;
+ struct timer_list debounce_timer;
};
static struct regmap_config mtk_dp_regmap_config = {
@@ -1970,6 +1972,9 @@ static irqreturn_t mtk_dp_hpd_event_thread(int hpd, void *dev)
if (event < 0)
return IRQ_HANDLED;
+ if (mtk_dp->need_debounce && mtk_dp->train_info.cable_plugged_in)
+ msleep(100);
+
if (mtk_dp->drm_dev) {
dev_info(mtk_dp->dev, "drm_helper_hpd_irq_event\n");
drm_helper_hpd_irq_event(mtk_dp->bridge.dev);
@@ -2047,6 +2052,11 @@ static irqreturn_t mtk_dp_hpd_isr_handler(struct mtk_dp *mtk_dp)
}
train_info->cable_state_change = true;
+ if (!train_info->cable_plugged_in) {
+ mod_timer(&mtk_dp->debounce_timer, jiffies + msecs_to_jiffies(100) - 1);
+ mtk_dp->need_debounce = false;
+ }
+
return IRQ_WAKE_THREAD;
}
@@ -2474,6 +2484,13 @@ static const struct drm_bridge_funcs mtk_dp_bridge_funcs = {
.detect = mtk_dp_bdg_detect,
};
+static void mtk_dp_debounce_timer(struct timer_list *t)
+{
+ struct mtk_dp *mtk_dp = from_timer(mtk_dp, t, debounce_timer);
+
+ mtk_dp->need_debounce = true;
+}
+
static int mtk_dp_probe(struct platform_device *pdev)
{
struct mtk_dp *mtk_dp;
@@ -2547,6 +2564,9 @@ static int mtk_dp_probe(struct platform_device *pdev)
else
mtk_dp->bridge.type = DRM_MODE_CONNECTOR_DisplayPort;
+ mtk_dp->need_debounce = true;
+ timer_setup(&mtk_dp->debounce_timer, mtk_dp_debounce_timer, 0);
+
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
@@ -2559,6 +2579,7 @@ static int mtk_dp_remove(struct platform_device *pdev)
platform_device_unregister(mtk_dp->phy_dev);
mtk_dp_video_mute(mtk_dp, true);
+ del_timer_sync(&mtk_dp->debounce_timer);
pm_runtime_disable(&pdev->dev);
--
2.35.1
next prev parent reply other threads:[~2022-05-23 10:53 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-23 10:47 [PATCH v10 00/21] drm/mediatek: Add mt8195 DisplayPort driver Guillaume Ranquet
2022-05-23 10:47 ` [PATCH v10 01/21] dt-bindings: mediatek,dpi: Add DPINTF compatible Guillaume Ranquet
2022-05-23 12:33 ` Rob Herring
2022-05-24 3:29 ` Chunfeng Yun
2022-05-25 11:55 ` AngeloGioacchino Del Regno
2022-06-07 2:31 ` Rex-BC Chen
2022-05-25 12:49 ` Maxime Ripard
2022-06-07 2:35 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 02/21] dt-bindings: mediatek,dp: Add Display Port binding Guillaume Ranquet
2022-05-24 3:35 ` Chunfeng Yun
2022-06-10 2:27 ` Rex-BC Chen
2022-05-25 15:30 ` AngeloGioacchino Del Regno
2022-06-10 2:29 ` Rex-BC Chen
2022-06-02 13:20 ` Rob Herring
2022-05-23 10:47 ` [PATCH v10 03/21] drm/edid: Convert cea_sad helper struct to kernelDoc Guillaume Ranquet
2022-05-23 10:57 ` Matthias Brugger
2022-06-07 2:44 ` Rex-BC Chen
2022-05-25 12:01 ` AngeloGioacchino Del Regno
2022-06-07 2:45 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 04/21] drm/edid: Add cea_sad helpers for freq/length Guillaume Ranquet
2022-05-25 12:26 ` AngeloGioacchino Del Regno
2022-06-10 6:50 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 05/21] video/hdmi: Add audio_infoframe packing for DP Guillaume Ranquet
2022-05-25 12:32 ` AngeloGioacchino Del Regno
2022-06-07 3:10 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 06/21] drm/mediatek: dpi: move dpi limits to SoC config Guillaume Ranquet
2022-05-23 10:47 ` [PATCH v10 07/21] drm/mediatek: dpi: implement a CK/DE pol toggle in " Guillaume Ranquet
2022-05-30 7:44 ` CK Hu
2022-06-07 2:54 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 08/21] drm/mediatek: dpi: implement a swap_input " Guillaume Ranquet
2022-05-30 7:50 ` CK Hu
2022-06-13 3:12 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 09/21] drm/mediatek: dpi: move dimension mask to " Guillaume Ranquet
2022-05-30 7:55 ` CK Hu
2022-05-23 10:47 ` [PATCH v10 10/21] drm/mediatek: dpi: move hvsize_mask " Guillaume Ranquet
2022-05-30 8:21 ` CK Hu
2022-05-23 10:47 ` [PATCH v10 11/21] drm/mediatek: dpi: move swap_shift " Guillaume Ranquet
2022-05-30 8:38 ` CK Hu
2022-06-02 11:38 ` Rex-BC Chen
2022-06-02 12:19 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 12/21] drm/mediatek: dpi: move the yuv422_en_bit " Guillaume Ranquet
2022-05-30 8:47 ` CK Hu
2022-05-23 10:47 ` [PATCH v10 13/21] drm/mediatek: dpi: move the csc_enable bit " Guillaume Ranquet
2022-05-23 10:47 ` [PATCH v10 14/21] drm/mediatek: dpi: Add dpintf support Guillaume Ranquet
2022-05-25 12:58 ` AngeloGioacchino Del Regno
2022-06-13 6:10 ` Rex-BC Chen
2022-06-02 5:48 ` Christophe JAILLET
2022-06-13 6:05 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 15/21] drm/mediatek: dpi: Only enable dpi after the bridge is enabled Guillaume Ranquet
2022-05-23 10:47 ` [PATCH v10 16/21] drm/meditek: dpi: Add matrix_sel helper Guillaume Ranquet
2022-05-23 10:47 ` [PATCH v10 17/21] phy: phy-mtk-dp: Add driver for DP phy Guillaume Ranquet
2022-06-08 16:31 ` Vinod Koul
2022-05-23 10:47 ` [PATCH v10 18/21] drm/mediatek: Add mt8195 Embedded DisplayPort driver Guillaume Ranquet
2022-05-25 5:47 ` CK Hu
2022-05-30 9:34 ` CK Hu
2022-05-30 10:08 ` CK Hu
2022-06-07 6:21 ` CK Hu
2022-06-07 12:24 ` Rex-BC Chen
2022-06-08 2:23 ` CK Hu
2022-06-08 8:43 ` Rex-BC Chen
2022-06-08 9:15 ` CK Hu
2022-06-08 11:52 ` Rex-BC Chen
2022-06-07 6:44 ` CK Hu
2022-06-07 12:44 ` Rex-BC Chen
2022-06-08 2:44 ` CK Hu
2022-06-08 12:54 ` Rex-BC Chen
2022-06-07 7:30 ` CK Hu
2022-06-07 12:46 ` Rex-BC Chen
2022-06-07 7:47 ` CK Hu
2022-06-08 10:26 ` Rex-BC Chen
2022-06-09 2:30 ` CK Hu
2022-06-09 7:24 ` Rex-BC Chen
2022-06-07 8:01 ` CK Hu
2022-06-09 7:18 ` Rex-BC Chen
2022-06-07 8:12 ` CK Hu
2022-06-07 12:55 ` Rex-BC Chen
2022-06-07 9:04 ` CK Hu
2022-06-09 8:00 ` Rex-BC Chen
2022-06-08 8:30 ` CK Hu
2022-06-09 8:03 ` Rex-BC Chen
2022-06-08 8:45 ` CK Hu
2022-06-08 8:54 ` Rex-BC Chen
2022-06-09 9:37 ` CK Hu
2022-06-10 2:10 ` Rex-BC Chen
2022-05-23 10:47 ` [PATCH v10 19/21] drm/mediatek: Add mt8195 External DisplayPort support Guillaume Ranquet
2022-05-25 13:04 ` AngeloGioacchino Del Regno
2022-05-23 10:47 ` Guillaume Ranquet [this message]
2022-05-23 10:47 ` [PATCH v10 21/21] drm/mediatek: DP audio support for mt8195 Guillaume Ranquet
2022-06-02 3:50 ` [PATCH v10 00/21] drm/mediatek: Add mt8195 DisplayPort driver Rex-BC Chen
2022-06-02 5:31 ` Rex-BC Chen
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