From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1AA1C184 for ; Tue, 23 Sep 2025 02:58:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758596285; cv=none; b=i8lFE+eTWeh300mWn7OIy7Lg5m2TJAEulI0qj4ItfCkRX0/M7rBSTJHCG3ooTUvPJeHAn5LSEJ+Xe71WB+d5mW3jXICC89YcylMe8pzIpsetrSEIfZE8T2QI4WyBdvR6nBw9BRAVsxghkSxa/4SALJDkc9du7hMUXwVRG7KoOsk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758596285; c=relaxed/simple; bh=Iae//nvp9B8tGWtD5t/4BeZC+YINkDe/MB8n2g1lAfw=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=MUl7hcd2EUABC4JOUcbq1Gw645US0prG2RzvhRv5pDkqn4fE1H2FbABIG/2ySk5l9Ho7TOHdVGoEPlfhoVkIn5PIfXrTG/bWLTeL9hiGYz76VLBZOaqZnYIw9csMcwMbnlOViM7AOm7tjf1knok0wgm0wqETMAJgxbcWrbDnCa0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.163.44]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4cW4M60rJJz24hvM; Tue, 23 Sep 2025 10:54:26 +0800 (CST) Received: from dggemv712-chm.china.huawei.com (unknown [10.1.198.32]) by mail.maildlp.com (Postfix) with ESMTPS id E93F314010D; Tue, 23 Sep 2025 10:57:57 +0800 (CST) Received: from kwepemq100007.china.huawei.com (7.202.195.175) by dggemv712-chm.china.huawei.com (10.1.198.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 23 Sep 2025 10:57:57 +0800 Received: from [10.159.166.136] (10.159.166.136) by kwepemq100007.china.huawei.com (7.202.195.175) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Tue, 23 Sep 2025 10:57:57 +0800 Message-ID: <5e9aad79-fef1-4258-83c4-6938ceafbaa5@huawei.com> Date: Tue, 23 Sep 2025 10:57:56 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 drm-dp 1/4] drm/hisilicon/hibmc: fix dp probabilistical detect errors after HPD irq To: Dmitry Baryshkov CC: , , , , , , , , , , , , , , , , References: <20250922024943.311947-1-shiyongbang@huawei.com> <20250922024943.311947-2-shiyongbang@huawei.com> <4vtis3tmlxhmxjmzhi4jdfriexidtr5u2jdcpmfegyyc5gkznu@mpzganc4k5gp> From: Yongbang Shi In-Reply-To: <4vtis3tmlxhmxjmzhi4jdfriexidtr5u2jdcpmfegyyc5gkznu@mpzganc4k5gp> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemq100007.china.huawei.com (7.202.195.175) > On Mon, Sep 22, 2025 at 10:49:40AM +0800, Yongbang Shi wrote: >> From: Baihan Li >> >> The issue is that drm_connector_helper_detect_from_ddc() returns wrong >> status when plugging or unplugging the monitor. Use HPD pin status in >> DP's detect_ctx() for real physcal monitor in/out, and keep using >> detect_frome_ddc() if it's the first time to call detect because of >> insmoding driver. > If I understand correct, this is not quite right. Consider DP-to-HDMI or > DP-to-DVI dongle being plugged without an actual monitor and then the > monitor being plugged later on. Hi Dmitry, Thanks for your correction. So your point is that if the HPD comes in from a dongle. Is that okay to add those checks at the end? ret = drm_dp_read_dpcd_caps(dp_dev->aux, dp_dev->dpcd); if (ret) return connector_status_disconnected; if (!drm_dp_is_branch(dpcd)) return connector_status_connected; if (drm_dp_read_sink_count_cap(connector, dp_dev->dpcd, &dp_dev->desc) && dp_dev->dpcd[DP_DOWNSTREAM_PORT_0] & DP_DS_PORT_HPD) { ret = drm_dp_read_sink_count(dp_dev->dpcd); if (ret > 0) return connector_status_connected; } Thanks， Baihan >> Fixes: 3c7623fb5bb6 ("drm/hisilicon/hibmc: Enable this hot plug detect of irq feature") >> Signed-off-by: Baihan Li >> Signed-off-by: Yongbang Shi >> --- >> ChangeLog: >> v5 -> v6: >> - use HPD status in DP detect_ctx(), suggested by Dmitry Baryshkov. >> v4 -> v5: >> - fix the commit message and DP detect_ctx(), suggested by Dmitry Baryshkov. >> --- >> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 12 ++++++++++++ >> drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h | 7 +++++++ >> drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h | 3 +++ >> drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c | 13 +++++++++++-- >> 4 files changed, 33 insertions(+), 2 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..4d8d3e4d4f84 100644 >> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c >> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c >> @@ -2,6 +2,7 @@ >> // Copyright (c) 2024 Hisilicon Limited. >> >> #include >> +#include >> #include >> #include "dp_config.h" >> #include "dp_comm.h" >> @@ -305,3 +306,14 @@ void hibmc_dp_set_cbar(struct hibmc_dp *dp, const struct hibmc_dp_cbar_cfg *cfg) >> hibmc_dp_reg_write_field(dp_dev, HIBMC_DP_COLOR_BAR_CTRL, BIT(0), cfg->enable); >> writel(HIBMC_DP_SYNC_EN_MASK, dp_dev->base + HIBMC_DP_TIMING_SYNC_CTRL); >> } >> + >> +void hibmc_dp_update_hpd_status(struct hibmc_dp *dp) >> +{ >> + int status; >> + >> + readl_poll_timeout(dp->dp_dev->base + HIBMC_DP_HPD_STATUS, status, >> + FIELD_GET(HIBMC_DP_HPD_CUR_STATE, status) != dp->hpd_status, >> + 1000, 100000); /* DP spec says 100ms */ >> + >> + dp->hpd_status = FIELD_GET(HIBMC_DP_HPD_CUR_STATE, status); >> +} >> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h >> index 665f5b166dfb..8348ad9e34a8 100644 >> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h >> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.h >> @@ -14,6 +14,11 @@ >> >> struct hibmc_dp_dev; >> >> +enum hibmc_hpd_status { >> + HIBMC_HPD_OUT, >> + HIBMC_HPD_IN, >> +}; >> + >> enum hibmc_dp_cbar_pattern { >> CBAR_COLOR_BAR, >> CBAR_WHITE, >> @@ -50,6 +55,7 @@ struct hibmc_dp { >> struct drm_dp_aux aux; >> struct hibmc_dp_cbar_cfg cfg; >> u32 irq_status; >> + int hpd_status; >> }; >> >> int hibmc_dp_hw_init(struct hibmc_dp *dp); >> @@ -60,5 +66,6 @@ void hibmc_dp_reset_link(struct hibmc_dp *dp); >> void hibmc_dp_hpd_cfg(struct hibmc_dp *dp); >> void hibmc_dp_enable_int(struct hibmc_dp *dp); >> void hibmc_dp_disable_int(struct hibmc_dp *dp); >> +void hibmc_dp_update_hpd_status(struct hibmc_dp *dp); >> >> #endif >> diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h >> index 394b1e933c3a..64306abcd986 100644 >> --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h >> +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h >> @@ -24,6 +24,9 @@ >> #define HIBMC_DP_CFG_AUX_READY_DATA_BYTE GENMASK(16, 12) >> #define HIBMC_DP_CFG_AUX GENMASK(24, 17) >> >> +#define HIBMC_DP_HPD_STATUS 0x98 >> +#define HIBMC_DP_HPD_CUR_STATE GENMASK(7, 4) >> + >> #define HIBMC_DP_PHYIF_CTRL0 0xa0 >> #define HIBMC_DP_CFG_SCRAMBLE_EN BIT(0) >> #define HIBMC_DP_CFG_PAT_SEL GENMASK(7, 4) >> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c >> index d06832e62e96..48c9c97eef0e 100644 >> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c >> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_dp.c >> @@ -34,9 +34,16 @@ 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_dp *dp = to_hibmc_dp(connector); >> + >> + /* if no HPD just probe DDC */ >> + if (!dp->irq_status) >> + return drm_connector_helper_detect_from_ddc(connector, ctx, force); >> >> - return drm_connector_helper_detect_from_ddc(connector, ctx, force); >> + if (dp->hpd_status == HIBMC_HPD_IN) >> + return connector_status_connected; >> + >> + return connector_status_disconnected; >> } >> >> static const struct drm_connector_helper_funcs hibmc_dp_conn_helper_funcs = { >> @@ -128,6 +135,8 @@ irqreturn_t hibmc_dp_hpd_isr(int irq, void *arg) >> hibmc_dp_reset_link(&priv->dp); >> } >> >> + hibmc_dp_update_hpd_status(&priv->dp); >> + >> if (dev->registered) >> drm_connector_helper_hpd_irq_event(&priv->dp.connector); >> >> -- >> 2.33.0 >>