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 3C89FC3DA6E for ; Fri, 5 Jan 2024 13:11:54 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 96ABE10E00B; Fri, 5 Jan 2024 13:11:53 +0000 (UTC) Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.12]) by gabe.freedesktop.org (Postfix) with ESMTPS id CA48510E5CB for ; Fri, 5 Jan 2024 13:11:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1704460312; x=1735996312; h=date:from:to:cc:subject:message-id:reply-to:references: mime-version:content-transfer-encoding:in-reply-to; bh=MArBNVg3xL4EaUHHSahRlPfn+CitxNGdZHEp9MZrOOQ=; b=hqqbJmdYkCBO7jxHj0vXXipzpQXF5kOrkHySTQeXIHufc5n+bLDh2VT5 o+2nWkr3uElYahnQ5ec9cIDH4s0P/3QvDbBCyOrjHgAiovPAbNEVvFzqJ td19wjKqXmqwU1fhdAkZOhggYkOGysQAaKpbooehFYpQXlkgunhMiDu3I Ch/egNp0/U6WZ+13S/4xwvxgo378+tHRjl7+MBYFv6VP9jgiYyJA4eevj 46KXAT4DW0KW8ppuSh/ibDzE3neQcNgG8E8MAmFe9rzz3oGxUTYwW2OIk HD2F+u82+gtJluKC3rVWAURxp0BghnR+lbl36tguogcL/jnimm4J8U0YB g==; X-IronPort-AV: E=McAfee;i="6600,9927,10943"; a="4873639" X-IronPort-AV: E=Sophos;i="6.04,333,1695711600"; d="scan'208";a="4873639" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orvoesa104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2024 05:11:51 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10943"; a="846573325" X-IronPort-AV: E=Sophos;i="6.04,333,1695711600"; d="scan'208";a="846573325" Received: from ideak-desk.fi.intel.com ([10.237.72.78]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Jan 2024 05:11:50 -0800 Date: Fri, 5 Jan 2024 15:12:00 +0200 From: Imre Deak To: "Hogander, Jouni" Subject: Re: [PATCH 01/12] drm/i915: Init DRM connector polled field early Message-ID: References: <20240104083008.2715733-1-imre.deak@intel.com> <20240104083008.2715733-2-imre.deak@intel.com> <9ac27342f4402fe90c1233b88ed92c89580e206e.camel@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <9ac27342f4402fe90c1233b88ed92c89580e206e.camel@intel.com> 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: , Reply-To: imre.deak@intel.com Cc: "intel-gfx@lists.freedesktop.org" Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Fri, Jan 05, 2024 at 02:54:06PM +0200, Hogander, Jouni wrote: > On Thu, 2024-01-04 at 10:29 +0200, Imre Deak wrote: > > After an HPD IRQ storm on a connector intel_hpd_irq_storm_detect() > > will > > set the connector's HPD pin state to HPD_MARK_DISABLED and the IRQ > > gets > > disabled. Subsequently intel_hpd_irq_storm_switch_to_polling() will > > enable polling for these connectors, setting the pin state to > > HPD_DISABLED, but only if the connector's base.polled field is set to > > DRM_CONNECTOR_POLL_HPD. intel_hpd_irq_storm_reenable_work() will > > reenable the IRQ - after 2 minutes - if the pin state is > > HPD_DISABLED. > > > > The connectors will be created with their base.polled field set to 0, > > which gets initialized only later in i915_hpd_poll_init_work() (using > > intel_connector::polled). If a storm is detected on a connector after > > it's created and IRQs are enabled on it - by intel_hpd_init() - and > > before its bease.polled field is initialized in the above work, the > > connector's HPD pin will stay in the HPD_MARK_DISABLED state - > > leaving > > the IRQ disabled indefinitely - and polling will not get enabled on > > it as > > intended. > > > > I can't see a reason for initializing base.polled in a delayed > > manner, > > so do this already when creating the connector, to prevent the above > > race condition. > > To me it looks like intel_connector::polled is used just to store > original drm_connector::polled value and restore it in > intel_hpd_irq_storm_reenable_work: > > if (connector->base.polled != connector->polled) > drm_dbg(&dev_priv->drm, > "Reenabling HPD on connector %s\n", > connector->base.name); > connector->base.polled = connector->polled; Correct and restored similarly in i915_hpd_poll_init_work(). Originaly intel_connector::polled was added to avoid misconfiguring a connector's polled state in these two places if the two connectors share an HPD pin (one of them needing polling the other one using the HPD pin; not sure the exact scenario where this is actually possible). But I can't see why at this moment we couldn't initialize the original base.polled value early. > From this perspective it is right thing to do to initialize connector- > base.polled as you are doing in this patch. > > Reviewed-by: Jouni Högander > > > > > Signed-off-by: Imre Deak > > --- > > drivers/gpu/drm/i915/display/intel_crt.c | 1 + > > drivers/gpu/drm/i915/display/intel_dp.c | 1 + > > drivers/gpu/drm/i915/display/intel_dvo.c | 1 + > > drivers/gpu/drm/i915/display/intel_hdmi.c | 1 + > > drivers/gpu/drm/i915/display/intel_sdvo.c | 2 ++ > > drivers/gpu/drm/i915/display/intel_tv.c | 1 + > > 6 files changed, 7 insertions(+) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_crt.c > > b/drivers/gpu/drm/i915/display/intel_crt.c > > index abaacea5c2cc4..b330337b842a4 100644 > > --- a/drivers/gpu/drm/i915/display/intel_crt.c > > +++ b/drivers/gpu/drm/i915/display/intel_crt.c > > @@ -1069,6 +1069,7 @@ void intel_crt_init(struct drm_i915_private > > *dev_priv) > > } else { > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT; > > } > > + intel_connector->base.polled = intel_connector->polled; > > > > if (HAS_DDI(dev_priv)) { > > assert_port_valid(dev_priv, PORT_E); > > diff --git a/drivers/gpu/drm/i915/display/intel_dp.c > > b/drivers/gpu/drm/i915/display/intel_dp.c > > index 9ff0cbd9c0df5..fed649af8fc85 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dp.c > > +++ b/drivers/gpu/drm/i915/display/intel_dp.c > > @@ -6469,6 +6469,7 @@ intel_dp_init_connector(struct > > intel_digital_port *dig_port, > > connector->interlace_allowed = true; > > > > intel_connector->polled = DRM_CONNECTOR_POLL_HPD; > > + intel_connector->base.polled = intel_connector->polled; > > > > intel_connector_attach_encoder(intel_connector, > > intel_encoder); > > > > diff --git a/drivers/gpu/drm/i915/display/intel_dvo.c > > b/drivers/gpu/drm/i915/display/intel_dvo.c > > index 9111e9d46486d..83898ba493d16 100644 > > --- a/drivers/gpu/drm/i915/display/intel_dvo.c > > +++ b/drivers/gpu/drm/i915/display/intel_dvo.c > > @@ -536,6 +536,7 @@ void intel_dvo_init(struct drm_i915_private > > *i915) > > if (intel_dvo->dev.type == INTEL_DVO_CHIP_TMDS) > > connector->polled = DRM_CONNECTOR_POLL_CONNECT | > > DRM_CONNECTOR_POLL_DISCONNECT; > > + connector->base.polled = connector->polled; > > > > drm_connector_init_with_ddc(&i915->drm, &connector->base, > > &intel_dvo_connector_funcs, > > diff --git a/drivers/gpu/drm/i915/display/intel_hdmi.c > > b/drivers/gpu/drm/i915/display/intel_hdmi.c > > index eedef8121ff7c..55048c56bc527 100644 > > --- a/drivers/gpu/drm/i915/display/intel_hdmi.c > > +++ b/drivers/gpu/drm/i915/display/intel_hdmi.c > > @@ -3017,6 +3017,7 @@ void intel_hdmi_init_connector(struct > > intel_digital_port *dig_port, > > connector->ycbcr_420_allowed = true; > > > > intel_connector->polled = DRM_CONNECTOR_POLL_HPD; > > + intel_connector->base.polled = intel_connector->polled; > > > > if (HAS_DDI(dev_priv)) > > intel_connector->get_hw_state = > > intel_ddi_connector_get_hw_state; > > diff --git a/drivers/gpu/drm/i915/display/intel_sdvo.c > > b/drivers/gpu/drm/i915/display/intel_sdvo.c > > index 9218047495fb4..4e4a87f841787 100644 > > --- a/drivers/gpu/drm/i915/display/intel_sdvo.c > > +++ b/drivers/gpu/drm/i915/display/intel_sdvo.c > > @@ -2805,6 +2805,7 @@ intel_sdvo_dvi_init(struct intel_sdvo > > *intel_sdvo, u16 type) > > } else { > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT > > | DRM_CONNECTOR_POLL_DISCONNECT; > > } > > + intel_connector->base.polled = intel_connector->polled; > > encoder->encoder_type = DRM_MODE_ENCODER_TMDS; > > connector->connector_type = DRM_MODE_CONNECTOR_DVID; > > > > @@ -2880,6 +2881,7 @@ intel_sdvo_analog_init(struct intel_sdvo > > *intel_sdvo, u16 type) > > intel_connector = &intel_sdvo_connector->base; > > connector = &intel_connector->base; > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT; > > + intel_connector->base.polled = intel_connector->polled; > > encoder->encoder_type = DRM_MODE_ENCODER_DAC; > > connector->connector_type = DRM_MODE_CONNECTOR_VGA; > > > > diff --git a/drivers/gpu/drm/i915/display/intel_tv.c > > b/drivers/gpu/drm/i915/display/intel_tv.c > > index d4386cb3569e0..f3598fe39fda5 100644 > > --- a/drivers/gpu/drm/i915/display/intel_tv.c > > +++ b/drivers/gpu/drm/i915/display/intel_tv.c > > @@ -1990,6 +1990,7 @@ intel_tv_init(struct drm_i915_private > > *dev_priv) > > * More recent chipsets favour HDMI rather than integrated S- > > Video. > > */ > > intel_connector->polled = DRM_CONNECTOR_POLL_CONNECT; > > + intel_connector->base.polled = intel_connector->polled; > > > > drm_connector_init(&dev_priv->drm, connector, > > &intel_tv_connector_funcs, > > DRM_MODE_CONNECTOR_SVIDEO); >