From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DCF3422259C for ; Tue, 10 Jun 2025 10:53:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.16 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749552816; cv=none; b=thyjRqYG/4WiHB50xNEFZ9sTOHhHZ6Q/ajpY65JsdlQy7w10V1YW84pGt39SGdvM4ZINkdtfjKOdv3+Z4Ttev28DYN+6xuzAUVDT1PB/0eCsCEdQxTgRcSG0S2m1EYqwBEEbyTU6tZs20I9lXRl8EyrzanOhkFBmun9R+5zq3PE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1749552816; c=relaxed/simple; bh=/DZZ8mmbF4Shhai4foKWvywv6MHjfAF5Mt342aSPnPY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CkKQs2g+5bHh/Hq/KIdOIAaqlaPyts48Z5lxmxcHhY7KRrnQyk3gOVgKAM/xwSRh86+JCkIEptOqBqXjLeEZTiW4Fyy+exbIeQZGoCaR/TzulQtY6A9HLiu4dbP6BdpYbIqtJcT9tyJjlIOt8KVQxUP8zpgSbsZyOOXXnoHjEkE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=none smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=SyipRd40; arc=none smtp.client-ip=192.198.163.16 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="SyipRd40" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1749552815; x=1781088815; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=/DZZ8mmbF4Shhai4foKWvywv6MHjfAF5Mt342aSPnPY=; b=SyipRd40/fdxSsaBSdjHXqS1zO7wghQ+VSkqBPRvV6ePqTvtprCfVQ3j RBtA22LLfLdnHCilfcFWji1RRPbumXpZ7QWZ/hKAOZ8V8jMqEgZ1R6SDj 4779eFNFYR2UiRn4kpGfZJHUPmj1EIF3+3UVtfQpzj4h/y6gUTigx97GW Yo2yQ2Brmgr+8kVaHU1mLKdumUWtMYOLSkoMu7fFLAyFoB9tD9SRxD/Gr e3Xnwt9zak0CxdJbu6VU0J1x1d9JSf+zaE5Skoqb/hScvOUHij0Wzbz8X hOLd+ku9E7FIYg+UQDzix9olmtfWZfeVNP1v52Hapr10pN8y7P22UXq04 g==; X-CSE-ConnectionGUID: yj0h8w2jRxaLPbhNmaoDgw== X-CSE-MsgGUID: 0nbQgzcLQlucM23Pccot1w== X-IronPort-AV: E=McAfee;i="6800,10657,11459"; a="39274514" X-IronPort-AV: E=Sophos;i="6.16,224,1744095600"; d="scan'208";a="39274514" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by fmvoesa110.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2025 03:53:34 -0700 X-CSE-ConnectionGUID: 9mnfzALsSnyZDuqhQlSDHA== X-CSE-MsgGUID: jGAGc6ndRf+bdO6YIrQc9Q== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.16,224,1744095600"; d="scan'208";a="151813579" Received: from smile.fi.intel.com ([10.237.72.52]) by orviesa004.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Jun 2025 03:53:31 -0700 Received: from andy by smile.fi.intel.com with local (Exim 4.98.2) (envelope-from ) id 1uOwbf-00000005KIT-1Mi1; Tue, 10 Jun 2025 13:53:27 +0300 Date: Tue, 10 Jun 2025 13:53:27 +0300 From: Andy Shevchenko To: Arnd Bergmann Cc: Arnd Bergmann , Greg Kroah-Hartman , Riyan Dhiman , Thomas Zimmermann , Paolo Perego , Lorenzo Stoakes , Matthew Wilcox , Jeff Johnson , dri-devel@lists.freedesktop.org, linux-fbdev@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] fbtft: reduce stack usage Message-ID: References: <20250610092445.2640575-1-arnd@kernel.org> <088dc0a1-fc54-478c-b253-4ed5dd6d6bae@app.fastmail.com> Precedence: bulk X-Mailing-List: linux-staging@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <088dc0a1-fc54-478c-b253-4ed5dd6d6bae@app.fastmail.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo On Tue, Jun 10, 2025 at 12:35:14PM +0200, Arnd Bergmann wrote: > On Tue, Jun 10, 2025, at 12:26, Andy Shevchenko wrote: > > On Tue, Jun 10, 2025 at 11:24:38AM +0200, Arnd Bergmann wrote: ... > >> +static noinline_for_stack void fbtft_write_register_64(struct fbtft_par *par, > >> + int i, int buf[64]) > > > > Perhaps int i, int buf[64] should be u32? > > Right, I can send an updated patch, or this could be fixed up when applying > the patch Greg doesn't do that (or won't do anyway), so either a followup or a v2. ... > > Wondering if we may reuse this in other cases (by providing the additional > > length parameter). But it may be done later on. > > I tried this and that quickly became a mess. It is probably a good > idea to rework the code to completely avoid the varargs function > pointer and instead take an array here, but this is not something > I could easily do myself as that takes more time and needs better > testing. Right and this driver in any case in a frozen position, so it might never happen, though. -- With Best Regards, Andy Shevchenko