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 B4399C021A4 for ; Mon, 24 Feb 2025 15:11:37 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 306B910E18D; Mon, 24 Feb 2025 15:11:37 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Xf7aXe+J"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.9]) by gabe.freedesktop.org (Postfix) with ESMTPS id A5D4810E18D for ; Mon, 24 Feb 2025 15:11:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1740409895; x=1771945895; h=date:from:to:cc:subject:message-id:references: mime-version:content-transfer-encoding:in-reply-to; bh=qUzubzLgBT05RrsaQ4UBzMm3XMNcQZmfka4Vb8NPVi4=; b=Xf7aXe+J41UoptqyDI6XE8oU70pJb7n0Q+djFO5h18/mqFCetK+Si0zT zKJqSayspg+TKNSaiExKJXO388lWreJzsQO4/GG/4Ik3hUtHwlHNFfMA6 vLciCaAfw/+fHCWCjUZxI5ytRHB3h8jOUETjg5rHHh8nWEbzpFpWQLX9X rbliE106y+Iudrrcz4gcIa+KJjkMVmE5hcbZxaGQ/931TOPJ8OH7cbW4e 5yF/XJYwbTaaq3NgYfk/Bon3cluTszy63D1K6zO5d/WGwH3AFrxzIJKCZ 68PHuazQRJKLKqYJbld4YeR41oBlWKJSMQkOPYS/NonFf2/BexJhkIDAo w==; X-CSE-ConnectionGUID: O3bFbA4zS26H6M751PcnZA== X-CSE-MsgGUID: huYzrjAdRCCD6tXaAumZhg== X-IronPort-AV: E=McAfee;i="6700,10204,11355"; a="51806063" X-IronPort-AV: E=Sophos;i="6.13,309,1732608000"; d="scan'208";a="51806063" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by fmvoesa103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2025 07:11:35 -0800 X-CSE-ConnectionGUID: 4/Ao5ftqSSWETV+dElBn4g== X-CSE-MsgGUID: wU5cAz5sRvebytjsw+OlRw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,224,1728975600"; d="scan'208";a="153286520" Received: from smile.fi.intel.com ([10.237.72.58]) by orviesa001.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 24 Feb 2025 07:11:31 -0800 Received: from andy by smile.fi.intel.com with local (Exim 4.98) (envelope-from ) id 1tma7E-0000000EjB1-3EDe; Mon, 24 Feb 2025 17:11:28 +0200 Date: Mon, 24 Feb 2025 17:11:28 +0200 From: "andriy.shevchenko@linux.intel.com" To: Aditya Garg Cc: "maarten.lankhorst@linux.intel.com" , "mripard@kernel.org" , "tzimmermann@suse.de" , "airlied@gmail.com" , "simona@ffwll.ch" , Kerem Karabay , Atharva Tiwari , Aun-Ali Zaidi , Linux Kernel Mailing List , "dri-devel@lists.freedesktop.org" Subject: Re: [PATCH v4 2/2] drm/tiny: add driver for Apple Touch Bars in x86 Macs Message-ID: References: <844C1D39-4891-4DC2-8458-F46FA1B59FA0@live.com> <5BC3A795-99C2-4F00-ADD0-7ECD0285CDD0@live.com> <3D520B56-AE84-4D73-9604-495642AF5B30@live.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <3D520B56-AE84-4D73-9604-495642AF5B30@live.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, Feb 24, 2025 at 03:03:40PM +0000, Aditya Garg wrote: > > On 24 Feb 2025, at 8:27 PM, andriy.shevchenko@linux.intel.com wrote: > > On Mon, Feb 24, 2025 at 02:32:37PM +0000, Aditya Garg wrote: > >>> On 24 Feb 2025, at 7:30 PM, andriy.shevchenko@linux.intel.com wrote: > >>> On Mon, Feb 24, 2025 at 01:40:20PM +0000, Aditya Garg wrote: ... > >>>> +#define __APPLETBDRM_MSG_STR4(str4) ((__le32 __force)((str4[0] << 24) | (str4[1] << 16) | (str4[2] << 8) | str4[3])) > >>> > >>> As commented previously this is quite strange what's going on with endianess in > >>> this driver. Especially the above weirdness when get_unaligned_be32() is being > >>> open coded and force-cast to __le32. > >> > >> I would assume it was also mimicked from the Windows driver, though I haven't > >> really tried exploring this there. > >> > >> I’d rather be happy if you give me code change suggestions and let me review > >> and test them > > > > For the starter I would do the following for all related constants and > > drop that weird and ugly macros at the top (it also has an issue with > > the str4 length as it is 5 bytes long, not 4, btw): > > > > #define APPLETBDRM_MSG_CLEAR_DISPLAY cpu_to_le32(0x434c5244) /* CLRD */ > > Lemme test this. Just in case it won't work, reverse bytes in the integer. Because I was lost in this conversion. > > (assuming we stick with __leXX for now). This will be much less confusing. ... > >> Alright. For some reason (a mistake on my part), some dev_err_probe were also > >> still left in this version. > > > > But those are seems to me in the correct locations, no? How do we even know > > the DRM device before its creation? So, dev_err_probe() calls in ->probe() > > seem logical to me. Somebody from DRM should clarify this. > > Thomas asked me to do this change. Maybe you didn’t see his reply. I saw, maybe I took it wrong, but I really don't understand how on earth drm_err() or whatever can be used in real ->probe() of the physical device. Imagine the hypotetical case probe(strict device *dev) { mydrm; foo; ... foo = devm_gpiod_get(dev, ...); if (IS_ERR(foo)) return dev_err_probe(dev, ...); // how?! ... mydrm = ...DRM alloc...; ... } I don't even believe it will be possible to create drm_err_probe() as it most likely will require to have an allocation to be always the first op (that may fail) in the ->probe() which might be not the case for some device drivers. > >>>> + */ -- With Best Regards, Andy Shevchenko