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 7F7CAC05027 for ; Thu, 9 Feb 2023 13:10:45 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B5D5E10EAC2; Thu, 9 Feb 2023 13:10:44 +0000 (UTC) Received: from mga05.intel.com (mga05.intel.com [192.55.52.43]) by gabe.freedesktop.org (Postfix) with ESMTPS id 0840710EAC2; Thu, 9 Feb 2023 13:10:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1675948243; x=1707484243; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=O/vBPT8GM8Dr9BZ/ZfrdNmqBtCgatQbdkSLgfVSC1fs=; b=Qk6n8zied416q5k7j7sbe/jGBKeRMYApM29mzCJcwZLQyWhqcmVmJPql oC+tSyQu83H0U2gZpASlH8laOXlOl6U9oQCy+Tcw56FlC5wL5DHqWP4cW +YNlhXCcElBaXket/DU64OnHc/Suu8h30S6Kpl2A9RJDcEosmn5bCNjNo XKhqoiLbT0JJVmbylm64D0O5H6yyzHpI28/NudTjF2CLh77zRH4rpNb/w +WZkrX6tLgH4E2BrliXwBkdQGm4clTnmGw9nLvA3xPfUyyOKFEyUJzTJM Q5gegGiON7lm01Mch+U+60cK3jeKE7+NwKcohkWDd+sB1pNYl/U1OGKAk g==; X-IronPort-AV: E=McAfee;i="6500,9779,10615"; a="416320982" X-IronPort-AV: E=Sophos;i="5.97,283,1669104000"; d="scan'208";a="416320982" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Feb 2023 05:10:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10615"; a="731263182" X-IronPort-AV: E=Sophos;i="5.97,283,1669104000"; d="scan'208";a="731263182" Received: from stinkpipe.fi.intel.com (HELO stinkbox) ([10.237.72.55]) by fmsmga008.fm.intel.com with SMTP; 09 Feb 2023 05:10:39 -0800 Received: by stinkbox (sSMTP sendmail emulation); Thu, 09 Feb 2023 15:10:38 +0200 Date: Thu, 9 Feb 2023 15:10:38 +0200 From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= To: Pekka Paalanen Message-ID: References: <20230208040911.12590-2-ville.syrjala@linux.intel.com> <20230208211016.7034-1-ville.syrjala@linux.intel.com> <20230209135855.22cf1b32.pekka.paalanen@collabora.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20230209135855.22cf1b32.pekka.paalanen@collabora.com> X-Patchwork-Hint: comment Subject: Re: [Intel-gfx] [PATCH v2 1/2] drm: Introduce plane SIZE_HINTS property 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: , Cc: Simon Ser , intel-gfx@lists.freedesktop.org, Daniel Stone , Jonas =?iso-8859-1?Q?=C5dahl?= , dri-devel@lists.freedesktop.org, Harry Wentland Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Thu, Feb 09, 2023 at 01:58:55PM +0200, Pekka Paalanen wrote: > On Wed, 8 Feb 2023 23:10:16 +0200 > Ville Syrjala wrote: > > > From: Ville Syrjälä > > > > Add a new immutable plane property by which a plane can advertise > > a handful of recommended plane sizes. This would be mostly exposed > > by cursor planes as a slightly more capable replacement for > > the DRM_CAP_CURSOR_WIDTH/HEIGHT caps, which can only declare > > a one size fits all limit for the whole device. > > > > Currently eg. amdgpu/i915/nouveau just advertize the max cursor > > size via the cursor size caps. But always using the max sized > > cursor can waste a surprising amount of power, so a better > > stragey is desirable. > > > > Most other drivers don't specify any cursor size at all, in > > which case the ioctl code just claims that 64x64 is a great > > choice. Whether that is actually true is debatable. > > > > A poll of various compositor developers informs us that > > blindly probing with setcursor/atomic ioctl to determine > > suitable cursor sizes is not acceptable, thus the > > introduction of the new property to supplant the cursor > > size caps. The compositor will now be free to select a > > more optimal cursor size from the short list of options. > > > > Note that the reported sizes (either via the property or the > > caps) make no claims about things such as plane scaling. So > > these things should only really be consulted for simple > > "cursor like" use cases. > > > > v2: Try to add some docs > > > > Cc: Simon Ser > > Cc: Jonas Ådahl > > Cc: Daniel Stone > > Cc: Pekka Paalanen > > Acked-by: Harry Wentland > > Signed-off-by: Ville Syrjälä > > --- > > drivers/gpu/drm/drm_mode_config.c | 7 +++++ > > drivers/gpu/drm/drm_plane.c | 48 +++++++++++++++++++++++++++++++ > > include/drm/drm_mode_config.h | 5 ++++ > > include/drm/drm_plane.h | 4 +++ > > include/uapi/drm/drm_mode.h | 11 +++++++ > > 5 files changed, 75 insertions(+) > > > > diff --git a/drivers/gpu/drm/drm_mode_config.c b/drivers/gpu/drm/drm_mode_config.c > > index 87eb591fe9b5..21860f94a18c 100644 > > --- a/drivers/gpu/drm/drm_mode_config.c > > +++ b/drivers/gpu/drm/drm_mode_config.c > > @@ -374,6 +374,13 @@ static int drm_mode_create_standard_properties(struct drm_device *dev) > > return -ENOMEM; > > dev->mode_config.modifiers_property = prop; > > > > + prop = drm_property_create(dev, > > + DRM_MODE_PROP_IMMUTABLE | DRM_MODE_PROP_BLOB, > > + "SIZE_HINTS", 0); > > + if (!prop) > > + return -ENOMEM; > > + dev->mode_config.size_hints_property = prop; > > + > > return 0; > > } > > > > diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c > > index 24e7998d1731..ae51b1f83755 100644 > > --- a/drivers/gpu/drm/drm_plane.c > > +++ b/drivers/gpu/drm/drm_plane.c > > @@ -140,6 +140,21 @@ > > * DRM_FORMAT_MOD_LINEAR. Before linux kernel release v5.1 there have been > > * various bugs in this area with inconsistencies between the capability > > * flag and per-plane properties. > > + * > > + * SIZE_HINTS: > > + * Blob property which contains the set of recommended plane size > > + * which can used for simple "cursor like" use cases (eg. no scaling). > > + * Using these hints frees userspace from extensive probing of > > + * supported plane sizes through atomic/setcursor ioctls. > > + * > > + * For optimal usage userspace should pick the smallest size > > + * that satisfies its own requirements. > > + * > > + * The blob contains an array of struct drm_plane_size_hint. > > + * > > + * Drivers should only attach this property to planes that > > + * support a very limited set of sizes (eg. cursor planes > > + * on typical hardware). > > Hi Ville, > > sounds good. Maybe a minor nit about "typical hardware". Would e.g. > "legacy PC hardware" be more accurate? "legacy" doesn't feel quite right for current and upcoming hardware. -- Ville Syrjälä Intel