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 201CECF9C71 for ; Mon, 23 Sep 2024 17:53:48 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id AA87E10E28B; Mon, 23 Sep 2024 17:53:47 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="cWhFQoZV"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id 2D24D10E28B for ; Mon, 23 Sep 2024 17:53:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1727114027; x=1758650027; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=lLciKUtqeBvi2pch0xaH51lBCg68MlSPiwJ8K0IDkeg=; b=cWhFQoZV/649+zvdMY745g9fAzvJ04Dz/qqTpplQnAj7mKqf4yDy/8P+ fkfH8nA+fSuFIIGZTDiVM+3xQoNeKsmwZLIxTFr51mXOC7WSdWdA/0TK8 VdWLwnxY/4M1d/sLx+hHIC9DxfJGVO25663PfojYKMYRnF7bYzcltG515 yoC8lqDs1454x7SmnvWgd1alPa6mfkqkX+BJliTbh9f7ZBpBZIFXez5/g AEh6cIfgMs+b2S3aPhaY/Wd9P5yCReQ7s1dbkIzszMuzNEfI0Sj+IZE3F pCaWvZYt1FDhsFN4VtvS9AR14YzLzo6tYFCHRGDBOxzC/J+KOqafjgYne g==; X-CSE-ConnectionGUID: geJGOspUQl2gfo+cyfrDoA== X-CSE-MsgGUID: B20tXmcjS6CvqFbcpARM1Q== X-IronPort-AV: E=McAfee;i="6700,10204,11204"; a="26268218" X-IronPort-AV: E=Sophos;i="6.10,252,1719903600"; d="scan'208";a="26268218" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by fmvoesa108.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 Sep 2024 10:53:41 -0700 X-CSE-ConnectionGUID: rtiTfZfJSKGkhX2AixHQzA== X-CSE-MsgGUID: zOQYLG2+Raqm8rFZIzWY5g== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,252,1719903600"; d="scan'208";a="71290008" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.74]) by fmviesa008.fm.intel.com with SMTP; 23 Sep 2024 10:53:39 -0700 Received: by stinkbox (sSMTP sendmail emulation); Mon, 23 Sep 2024 20:53:38 +0300 Date: Mon, 23 Sep 2024 20:53:38 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Suraj Kandpal Cc: intel-gfx@lists.freedesktop.org, uma.shankar@intel.com, matthew.d.roper@intel.com Subject: Re: [PATCH 1/2] drm/i915/hotplug: Reduce SHPD_FLITER_CNT for DISPLAY_VER() == 12 Message-ID: References: <20240923031007.1058072-2-suraj.kandpal@intel.com> <20240923031007.1058072-3-suraj.kandpal@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Patchwork-Hint: comment 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" On Mon, Sep 23, 2024 at 08:38:35PM +0300, Ville Syrjälä wrote: > On Mon, Sep 23, 2024 at 08:40:07AM +0530, Suraj Kandpal wrote: > > Reduce SHPD_CNT to 250us for display version 12 as it lines up > > with DP1.4a(Table3-4) spec. > > > > --v2 > > -Update commit message and comment [Matt] > > > > Signed-off-by: Suraj Kandpal > > --- > > drivers/gpu/drm/i915/display/intel_hotplug_irq.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c > > index 2c4e946d5575..8427386132e6 100644 > > --- a/drivers/gpu/drm/i915/display/intel_hotplug_irq.c > > +++ b/drivers/gpu/drm/i915/display/intel_hotplug_irq.c > > @@ -849,7 +849,11 @@ static void icp_hpd_irq_setup(struct drm_i915_private *dev_priv) > > enabled_irqs = intel_hpd_enabled_irqs(dev_priv, dev_priv->display.hotplug.pch_hpd); > > hotplug_irqs = intel_hpd_hotplug_irqs(dev_priv, dev_priv->display.hotplug.pch_hpd); > > > > - if (INTEL_PCH_TYPE(dev_priv) <= PCH_TGP) > > + /* > > + * We reduce the value to 250us to be able to detect SHPD when an external display > > + * is connected. This is also expected of us as stated in DP1.4a Table 3-4. > > + */ > > + if (INTEL_PCH_TYPE(dev_priv) < PCH_TGP) > > intel_uncore_write(&dev_priv->uncore, SHPD_FILTER_CNT, SHPD_FILTER_CNT_500_ADJ); > > else > > intel_uncore_write(&dev_priv->uncore, SHPD_FILTER_CNT, SHPD_FILTER_CNT_250); > > IMO if we start reducing this for older platforms then we > should just do it for all of them, instead of based on some > random cutoff. The other things we might want to think about are moving this into *_hpd_detection_setup() instead, and perhaps we should also start explicitly configuring SHPD_PULSE_CNT as well? -- Ville Syrjälä Intel