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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB426C4167B for ; Fri, 1 Dec 2023 09:19:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1377983AbjLAJS5 (ORCPT ); Fri, 1 Dec 2023 04:18:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229455AbjLAJS4 (ORCPT ); Fri, 1 Dec 2023 04:18:56 -0500 Received: from mail11.truemail.it (mail11.truemail.it [IPv6:2001:4b7e:0:8::81]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 778BE194 for ; Fri, 1 Dec 2023 01:19:02 -0800 (PST) Received: from francesco-nb.int.toradex.com (93-49-2-63.ip317.fastwebnet.it [93.49.2.63]) by mail11.truemail.it (Postfix) with ESMTPA id 47991207A1; Fri, 1 Dec 2023 10:18:58 +0100 (CET) Date: Fri, 1 Dec 2023 10:18:54 +0100 From: Francesco Dolcini To: Nishanth Menon Cc: Francesco Dolcini , Tony Lindgren , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Arnd Bergmann , Vignesh Raghavendra , Catalin Marinas , Will Deacon , Tero Kristo Subject: Re: [PATCH] arm64: defconfig: increase SERIAL_8250_NR_UARTS Message-ID: References: <20231130231657.12715-1-francesco@dolcini.it> <20231201060346.GE5169@atomide.com> <20231201064919.5mbmqo5fco7n3rgq@endnote> <20231201085957.uxvwe3l33n5fxfw4@unrushed> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231201085957.uxvwe3l33n5fxfw4@unrushed> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Dec 01, 2023 at 02:59:57AM -0600, Nishanth Menon wrote: > On 09:48-20231201, Francesco Dolcini wrote: > > On Fri, Dec 01, 2023 at 12:49:19AM -0600, Nishanth Menon wrote: > > > On 08:03-20231201, Tony Lindgren wrote: > > > > * Francesco Dolcini [231130 23:17]: > > > > > Increase CONFIG_SERIAL_8250_NR_UARTS from 4 to 8, the current legacy value > > > > > is not adequate for embedded systems that use SoCs where it's common to > > > > > have a large number of serial ports. > > > > > > > > > > No need to change CONFIG_SERIAL_8250_RUNTIME_UARTS, see commit 9d86719f8769 > > > > > ("serial: 8250: Allow using ports higher than SERIAL_8250_RUNTIME_UARTS"). > > > > > > > > > > This enables using the UART connected Bluetooth device on Verdin AM62 > > > > > board. > > > > > > I'd prefer to get Arnd's view on the topic as well (I kind of > > > recollect some historic discussion which I am not failing to trace > > > that there usage model doesn't exceed 4 and aliases could be used to > > > map these as required for the platform). > > > > The usage model that triggered this change exceed 4, we >4 uart in > > use at the same time. > > > > And the issue is not really "distro use", and I do not think anything > > about aliases matter (the BT device is described as a child of the uart > > in the DT). > > > > &main_uart5 { > > bluetooth { > > compatible = "nxp,88w8987-bt"; > > }; > > }; > > > > The change here is required to have basic hardware functionalities > > working for kernel development and debugging using the in-tree > > defconfig. > > I'd suggest to elaborate on "This enables using the UART connected > Bluetooth device on Verdin AM62 board." I can do this, of course, I'll wait for some more feedback in the coming days as you somehow already suggested. Francesco