Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933255Ab2HVSZu (ORCPT ); Wed, 22 Aug 2012 14:25:50 -0400 Received: from relais.videotron.ca ([24.201.245.36]:38870 "EHLO relais.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933220Ab2HVSZq (ORCPT ); Wed, 22 Aug 2012 14:25:46 -0400 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: TEXT/PLAIN; CHARSET=US-ASCII Date: Wed, 22 Aug 2012 14:25:45 -0400 (EDT) From: Nicolas Pitre To: Olof Johansson Cc: Philip Rakity , Doug Anderson , Jaehoon Chung , "linux-mmc@vger.kernel.org" , Alim Akhtar , Thomas P Abraham , Chris Ball , Will Newton , Seungwon Jeon , James Hogan , "linux-kernel@vger.kernel.org" , Linus Walleij , Ulf Hansson , Adrian Hunter Subject: Re: [PATCH 1/2] mmc: core: Add a capability for disabling mmc cards In-reply-to: Message-id: References: <1345608318-15347-1-git-send-email-dianders@chromium.org> <50346181.3010406@samsung.com> <5ED03810-753A-407D-A994-E1FD22BE45E6@marvell.com> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2126 Lines: 56 On Wed, 22 Aug 2012, Olof Johansson wrote: > On Wed, Aug 22, 2012 at 9:00 AM, Philip Rakity wrote: > > > > On Aug 22, 2012, at 8:44 AM, Doug Anderson wrote: > > > >> Thanks for your feedback. In this case I have a card that is an MMC > >> card so mmc_attach_sdio() and mmc_attach_sd() will fail. If I let > >> mmc_attach_mmc() run it will actually find the MMC card. However, on > >> this platform it is not valid to recognize MMC cards. > >> > > > > > > Understand. > > > > Can you explain why the change is needed. Is it for technical > > reasons that MMC is not allowed -- if so then I do not understand how SD can work > > and MMC cannot. > > > > If it is for marketing reasons -- then --- oh well ..... > > > > > > Could you add some additional comments to the commit message. > > I think it makes sense to handle all 3 cases > > a) SDIO not allowed > > b) SD not allowed > > c) MMC not allowed > > We are working with a system manufacturer who wishes to only support > SD cards in their product, and need to accommodate that. It made sense > for us to contribute this work upstream since others might want to do > the same in the future for some reason. > > Adding all three cases makes sense if others foresee a use case for it. Isn't this rather revolting? Personally I find such "feature" totally ridiculous. If said manufacturer doesn't want to support MMC cards, they just have to not advertise it, period. Or if they really mean it, then they only have to state it explicitly in their user manual, and repeat it if ever problems are reported. Dumbing down kernel functionality to serve marketing purpose or technology lock-ins is utterly stupid. Purposely restricting interoperability might even be ruled illegal in some jurisdictions. I therefore insist on providing a vehement NAK on such patches. Nicolas -- 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/