From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E6644C0015E for ; Wed, 9 Aug 2023 10:43:03 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 07DFE10E416; Wed, 9 Aug 2023 10:43:02 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [192.55.52.115]) by gabe.freedesktop.org (Postfix) with ESMTPS id 99CE110E046 for ; Wed, 9 Aug 2023 10:42:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1691577776; x=1723113776; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=IH8td+18k9nn5DPD3ww7fjWAHfO+R3CHE85TLJ06hxk=; b=i8xowpWoZucKHn/gCImduJxBsAmW9cTjJz516ZKuNwKKvgccuBR58T6C CGofZ/4AkP0QsiUxJHhaZR8014vMepuUyDVayxSJTW/hCWiRZN3FRb4OK L3p0frSBiUjjMGXQ4w8r8yZN5G9ycigeionAFyKKmQl0iNpqr9brcZZ7h vp2+PJlw1woz3qCBm8zIeocAAeUVmulnhBUoDJA8GbNAz3xwUU4vFSGYb QJLh3JZMZNC8fFqFMdrjAgr/BBjE+s3c9U3GffnuX4gHrRM/nXfZtmURM 8Zo67Kp47SQFbI2Dr1CeDvdmucdhIB0F+6IGPaMnh2zHmcftGaUW3AZq5 Q==; X-IronPort-AV: E=McAfee;i="6600,9927,10795"; a="371078477" X-IronPort-AV: E=Sophos;i="6.01,159,1684825200"; d="scan'208";a="371078477" Received: from orsmga008.jf.intel.com ([10.7.209.65]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2023 03:42:55 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10795"; a="761335921" X-IronPort-AV: E=Sophos;i="6.01,159,1684825200"; d="scan'208";a="761335921" Received: from ideak-desk.fi.intel.com ([10.237.72.78]) by orsmga008-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Aug 2023 03:42:54 -0700 From: Imre Deak To: intel-gfx@lists.freedesktop.org Date: Wed, 9 Aug 2023 13:43:05 +0300 Message-Id: <20230809104307.1218058-1-imre.deak@intel.com> X-Mailer: git-send-email 2.37.2 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Intel-gfx] [CI 1/3] drm/i915: Avoid endless HPD poll detect loop via runtime suspend/resume X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" The issue fixed in commit a8ddac7c9f06 ("drm/i915: Avoid HPD poll detect triggering a new detect cycle") on VLV, CHV is still present on platforms where the display hotplug detection functionality is available whenever the device is in D0 state (hence these platforms switch to HPD polling only when the device is runtime suspended). The above commit avoids an endless i915_hpd_poll_init_work() -> connector detect loop by making sure that by the end of i915_hpd_poll_init_work() all display power references acquired by the connector detect functions which can trigger a new cycle (display core power domain) are dropped. However on platforms where HPD polling is enabled/disabled only from the runtime suspend/resume handlers, this is not ensured: for instance eDP VDD, TypeC port PHYs and the runtime autosuspend delay may still keep the device runtime resumed (via a power reference acquired during connector detection and hence result in an endless loop like the above). Solve the problem described in the above commit on all platforms, by making sure that a i915_hpd_poll_init_work() -> connector detect sequence can't take any power reference in the first place which would trigger a new cycle, instead of relying on these power references to be dropped by the end of the sequence. With the default runtime autosuspend delay (10 sec) this issue didn't happen in practice, since the device remained runtime resumed for the whole duration of the above sequence. CI/IGT tests however set the autosuspend delay to 0, which makes the problem visible, see References: below. Tested on GLK, CHV. v2: Don't warn about a requeued work, to account for disabling polling directly during driver loading, reset and system resume. References: https://gitlab.freedesktop.org/drm/intel/-/issues/7940#note_1997403 Signed-off-by: Imre Deak Reviewed-by: Jouni Högander --- drivers/gpu/drm/i915/display/intel_crt.c | 6 ------ drivers/gpu/drm/i915/display/intel_dp.c | 6 ------ drivers/gpu/drm/i915/display/intel_hdmi.c | 6 ------ drivers/gpu/drm/i915/display/intel_hotplug.c | 22 +++++++++++++++++++- 4 files changed, 21 insertions(+), 19 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_crt.c b/drivers/gpu/drm/i915/display/intel_crt.c index 8090747586877..f66340b4caf0f 100644 --- a/drivers/gpu/drm/i915/display/intel_crt.c +++ b/drivers/gpu/drm/i915/display/intel_crt.c @@ -907,12 +907,6 @@ intel_crt_detect(struct drm_connector *connector, out: intel_display_power_put(dev_priv, intel_encoder->power_domain, wakeref); - /* - * Make sure the refs for power wells enabled during detect are - * dropped to avoid a new detect cycle triggered by HPD polling. - */ - intel_display_power_flush_work(dev_priv); - return status; } diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 12bd2f322e627..964bf0551bdc9 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -4957,12 +4957,6 @@ intel_dp_detect(struct drm_connector *connector, if (status != connector_status_connected && !intel_dp->is_mst) intel_dp_unset_edid(intel_dp); - /* - * Make sure the refs for power wells enabled during detect are - * dropped to avoid a new detect cycle triggered by HPD polling. - */ - intel_display_power_flush_work(dev_priv); - if (!intel_dp_is_edp(intel_dp)) drm_dp_set_subconnector_property(connector, status, diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c b/drivers/gpu/drm/i915/display/intel_hdmi.c index 94a7e1537f427..9442bf43550ee 100644 --- a/drivers/gpu/drm/i915/display/intel_hdmi.c +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c @@ -2522,12 +2522,6 @@ intel_hdmi_detect(struct drm_connector *connector, bool force) if (status != connector_status_connected) cec_notifier_phys_addr_invalidate(intel_hdmi->cec_notifier); - /* - * Make sure the refs for power wells enabled during detect are - * dropped to avoid a new detect cycle triggered by HPD polling. - */ - intel_display_power_flush_work(dev_priv); - return status; } diff --git a/drivers/gpu/drm/i915/display/intel_hotplug.c b/drivers/gpu/drm/i915/display/intel_hotplug.c index 0ff5ed46ae1e7..dd7eb9fc78610 100644 --- a/drivers/gpu/drm/i915/display/intel_hotplug.c +++ b/drivers/gpu/drm/i915/display/intel_hotplug.c @@ -25,6 +25,7 @@ #include "i915_drv.h" #include "i915_irq.h" +#include "intel_display_power.h" #include "intel_display_types.h" #include "intel_hotplug.h" #include "intel_hotplug_irq.h" @@ -638,11 +639,25 @@ static void i915_hpd_poll_init_work(struct work_struct *work) display.hotplug.poll_init_work); struct drm_connector_list_iter conn_iter; struct intel_connector *connector; + intel_wakeref_t wakeref; bool enabled; mutex_lock(&dev_priv->drm.mode_config.mutex); enabled = READ_ONCE(dev_priv->display.hotplug.poll_enabled); + /* + * Prevent taking a power reference from this sequence of + * i915_hpd_poll_init_work() -> drm_helper_hpd_irq_event() -> + * connector detect which would requeue i915_hpd_poll_init_work() + * and so risk an endless loop of this same sequence. + */ + if (!enabled) { + wakeref = intel_display_power_get(dev_priv, + POWER_DOMAIN_DISPLAY_CORE); + drm_WARN_ON(&dev_priv->drm, + READ_ONCE(dev_priv->display.hotplug.poll_enabled)); + cancel_work(&dev_priv->display.hotplug.poll_init_work); + } drm_connector_list_iter_begin(&dev_priv->drm, &conn_iter); for_each_intel_connector_iter(connector, &conn_iter) { @@ -669,8 +684,13 @@ static void i915_hpd_poll_init_work(struct work_struct *work) * We might have missed any hotplugs that happened while we were * in the middle of disabling polling */ - if (!enabled) + if (!enabled) { drm_helper_hpd_irq_event(&dev_priv->drm); + + intel_display_power_put(dev_priv, + POWER_DOMAIN_DISPLAY_CORE, + wakeref); + } } /** -- 2.37.2