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 6E149CF9C6F for ; Mon, 23 Sep 2024 17:38:47 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EA21310E0EA; Mon, 23 Sep 2024 17:38:46 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="gwHB0T0h"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.14]) by gabe.freedesktop.org (Postfix) with ESMTPS id 87C3810E0EA for ; Mon, 23 Sep 2024 17:38:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1727113125; x=1758649125; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=xH+tiy5PwnKXDkpOp/yiW5D9Qj0t9W3pd0aGx5KLDg4=; b=gwHB0T0hAa9L108HXRDp+DWTTth8MabalEQFRs86tejbT9r0l+0UzD6l krNYQvWzDUCQHGBM+v3nei/dOf5iyAFG/Zb4vgAE0IcXDM+/qI7oqZAh0 Y+S4FkHpyXo/rH+MmOYRBIjf/+nsfR1fd7aVy/CnrrEQDP8HlKwG2HxHq u4gtK2LcN9kkeaDV/Ms1DQMVCEh3t0F0qbfTpJfVEofnTYwvbuiEmFrEs +PSS7FQqCwJZv37/xGAANlI4rjnsBZWfFT0dkmkje24JBgGU3RzLOROZJ PJ2iX1Qa9TCwkQvEST0eT25RtTjuyQ9nsQeXzqcILZpzLIZzxwMttKS2U Q==; X-CSE-ConnectionGUID: HslwbTKwQ7K71mc7NBSG5Q== X-CSE-MsgGUID: l+0QL9K5TY628VloczUdBA== X-IronPort-AV: E=McAfee;i="6700,10204,11204"; a="26266724" X-IronPort-AV: E=Sophos;i="6.10,252,1719903600"; d="scan'208";a="26266724" 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 10:38:38 -0700 X-CSE-ConnectionGUID: PmxJxjagRFiiPTDVREysDQ== X-CSE-MsgGUID: IxeU9b5zTDSgMCPd6V80+A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.10,252,1719903600"; d="scan'208";a="71287166" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.74]) by fmviesa008.fm.intel.com with SMTP; 23 Sep 2024 10:38:36 -0700 Received: by stinkbox (sSMTP sendmail emulation); Mon, 23 Sep 2024 20:38:35 +0300 Date: Mon, 23 Sep 2024 20:38:35 +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: <20240923031007.1058072-3-suraj.kandpal@intel.com> 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 08:40:07AM +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. -- Ville Syrjälä Intel