Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752819AbaATVoG (ORCPT ); Mon, 20 Jan 2014 16:44:06 -0500 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:58285 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750823AbaATVoE (ORCPT ); Mon, 20 Jan 2014 16:44:04 -0500 Date: Mon, 20 Jan 2014 21:43:05 +0000 From: Alan Cox To: Tushar Behera Cc: Russell King - ARM Linux , lkml , linux-serial , linux-samsung-soc , jslaby , Greg Kroah-Hartman , Ben Dooks , Mark Brown Subject: Re: [PATCH 1/2] serial: samsung: Move uart_register_driver call to device probe Message-ID: <20140120214305.54f65ffa@www.etchedpixels.co.uk> In-Reply-To: References: <1390208555-27770-1-git-send-email-tushar.behera@linaro.org> <1390208555-27770-2-git-send-email-tushar.behera@linaro.org> <20140120100530.GY15937@n2100.arm.linux.org.uk> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.20; x86_64-pc-linux-gnu) Face: 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 Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > I had earlier submitted a patch [1] to remove the hard coded > major/minor number for Samsung UART driver, but that was rejected > because of userspace breakage. Without this patch, Samsung UART driver > can't bind to the hard-coded device node. Changing the default > major/minor will also not help to fix the objections raised in [1]. > > Would you please suggest a way forward? > > [1] https://lkml.org/lkml/2013/12/27/2 The dynamic major/minor is the right patch. If the userspace breaks then the userspace was broken, but I see no evidence in the discussion that the userspace broke. 204,64 belongs to Altix so neither of the clashing drivers should use it. We had a table to stop messes like this, and we have dynamic numbering to stop the table being needed for the future 50 = /dev/ttyIOC0 Altix serial card ... 81 = /dev/ttyIOC31 Altix serial card Thats what the list says. Samsung should have followed the rules, they didn't so they get to pick up the pieces. The Amba driver wants moving as well. It's easy. If you want something to be ABI then make sure you get it upstream first, if not you get to own all the pain down the line. Hacking up the core code to paper over this crap is not on. We've been insisting firmly and robustly for years that people don't keep borrowing names and numbers they are not allocated, and use dynamic values whenever possible. If the hardware isn't present then the driver shouldn't even register with the tty layer in the first place so it doesn't make any resource differeneces either for properly written code. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/