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 6B222C2BA15 for ; Wed, 19 Jun 2024 13:24:22 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B11ED10EC9D; Wed, 19 Jun 2024 13:24:21 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="SgCsGUGI"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.18]) by gabe.freedesktop.org (Postfix) with ESMTPS id 920A110EC9D for ; Wed, 19 Jun 2024 13:24:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1718803459; x=1750339459; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=ELGZHP3zb1PjBN8z1UzTwCFZ2jC6megAjtHvhuiq5bQ=; b=SgCsGUGIBKqea6y21s7zo9yoyoy4/OyJlgZHqQwchDZrn2HTUcItj+Pk MHkAEyUZiZClJhrZI64mf+ZG+iltYukcsdAQYs1Xlp1qbbxdvvkxSJ95E eRK1NxeUY/yFHCGevy2UKmQNfUHZ3nOjx8pLn5613vdhV6klZvyhlguzJ Q/jT5KKULH6zFc9PrE+beHDmh4uEfKekek3twwrviP2dJ60x0K5xlQZNc ksLZ+Ujob411vw1LsWd0TCMRCX2lJWdjJWN5CQl3Y5Yqn6I2AlS/ruRPS kF5bJUOwaIOhYL7Pe55Yp1le6c+3qO1tUY1XystEhAf2aqFKwaWTeya4u A==; X-CSE-ConnectionGUID: h9nWFkgASx+KIsGdDIxNww== X-CSE-MsgGUID: yi7Ijo1wQiuJkOANGjdqcg== X-IronPort-AV: E=McAfee;i="6700,10204,11108"; a="15882595" X-IronPort-AV: E=Sophos;i="6.08,250,1712646000"; d="scan'208";a="15882595" Received: from fmviesa008.fm.intel.com ([10.60.135.148]) by orvoesa110.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 19 Jun 2024 06:24:18 -0700 X-CSE-ConnectionGUID: mw7RZHPYTficSSXy/HIdpA== X-CSE-MsgGUID: /3sBo9XsQM+QRLaxeJpg6w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.08,250,1712646000"; d="scan'208";a="41878067" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.74]) by fmviesa008.fm.intel.com with SMTP; 19 Jun 2024 06:24:16 -0700 Received: by stinkbox (sSMTP sendmail emulation); Wed, 19 Jun 2024 16:24:16 +0300 Date: Wed, 19 Jun 2024 16:24:16 +0300 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Jani Nikula Cc: intel-gfx@lists.freedesktop.org Subject: Re: [PATCH 08/11] drm/i915/dsb: Add i915.enable_dsb module parameter Message-ID: References: <20240611133344.30673-1-ville.syrjala@linux.intel.com> <20240611133344.30673-9-ville.syrjala@linux.intel.com> <875xu6h5kj.fsf@intel.com> <8734p9f577.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <8734p9f577.fsf@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 Wed, Jun 19, 2024 at 04:11:08PM +0300, Jani Nikula wrote: > On Wed, 19 Jun 2024, Ville Syrjälä wrote: > > On Tue, Jun 18, 2024 at 02:07:56PM +0300, Jani Nikula wrote: > >> On Tue, 11 Jun 2024, Ville Syrjala wrote: > >> > From: Ville Syrjälä > >> > > >> > As we extend the use of DSB for critical pipe/plane register > >> > programming, it'll be nice to have an escape valve at hand, > >> > in case things go very poorly. To that end, add a i915.enable_dsb > >> > modparam by which we can force the driver to take the pure mmio > >> > path instead. > >> > > >> > Signed-off-by: Ville Syrjälä > >> > --- > >> > drivers/gpu/drm/i915/display/intel_display_params.c | 3 +++ > >> > drivers/gpu/drm/i915/display/intel_display_params.h | 1 + > >> > drivers/gpu/drm/i915/display/intel_dsb.c | 3 +++ > >> > 3 files changed, 7 insertions(+) > >> > > >> > diff --git a/drivers/gpu/drm/i915/display/intel_display_params.c b/drivers/gpu/drm/i915/display/intel_display_params.c > >> > index aebdb7b59dbf..449a31767791 100644 > >> > --- a/drivers/gpu/drm/i915/display/intel_display_params.c > >> > +++ b/drivers/gpu/drm/i915/display/intel_display_params.c > >> > @@ -54,6 +54,9 @@ intel_display_param_named_unsafe(enable_dc, int, 0400, > >> > intel_display_param_named_unsafe(enable_dpt, bool, 0400, > >> > "Enable display page table (DPT) (default: true)"); > >> > > >> > +intel_display_param_named_unsafe(enable_dsb, bool, 0600, > >> > + "Enable display state buffer (DSB) (default: true)"); > >> > >> Not much point in leaving the module param 0600, is there? > > > > It'll let you try both dsb and mmio paths at runtime without > > having to do a full reboot/reload. > > I mean does any code actually look at the *module* parameter runtime? > It's only the initial value for the device param? You can change it via the debugfs i915_params/* thing. -- Ville Syrjälä Intel