From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Hunold Subject: Re: iMX53 and MMC_CAP_SDIO_IRQ Date: Mon, 12 Mar 2012 11:40:15 +0100 Message-ID: <4F5DD28F.50600@linuxtv.org> References: <4F5DB793.3080904@linuxtv.org> <20120312101037.GA2459@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from bar.sig21.net ([80.81.252.164]:49158 "EHLO bar.sig21.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753642Ab2CLKkZ (ORCPT ); Mon, 12 Mar 2012 06:40:25 -0400 In-Reply-To: <20120312101037.GA2459@pengutronix.de> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Wolfram Sang Cc: linux-mmc@vger.kernel.org, linux-arm-kernel@lists.infradead.org Hello Wolfram, thank you for your answer. on 12.03.2012 11:10 Wolfram Sang said the following: >> Probably this is a question for the Freescale people: why was the >> "mx_sdhci" necessary at all > > It probably was never necessary, it was just easier to hack on a forked > driver, because you can't break other sdhci-users, I guess. Since large > portions of the code are duplicated but issues have been fixed in a > very, ahem, custom manner, this was never suitable for mainline. Back > then, most vendors thought this is good enough. Luckily, times have > changed a bit. Yes, I know that thinking. >> and why is it not necessary any more? > > Because I wanted SD support in mainline, so I had to take a different > path. I understand. >> Any help, hints and historical informations are highly appreciated, >> before I start to look deeper into this problem. > > They don't have a common ancestor. Just dig into both, you will > recognize patterns, I guess. Ok, to sum this up: SDIO IRQs are working in mx_sdhci in the Freescale tree because it was properly implemented and tested, obviously. SDIO IRQs are working for sdhci in mainline probably for other non-freescale platforms. You fixed the generic sdhci driver in mainline to work with iMX53 to get rid of the need for mx_sdhci, but probably never got the chance to test if SDIO IRQs are really working. That means, the subtle difference between mx_sdhci and sdhci to get SDIO IRQS to work on sdhci with iMX53 has yet to be found. > Regards, > Wolfram CU Michael. From mboxrd@z Thu Jan 1 00:00:00 1970 From: hunold@linuxtv.org (Michael Hunold) Date: Mon, 12 Mar 2012 11:40:15 +0100 Subject: iMX53 and MMC_CAP_SDIO_IRQ In-Reply-To: <20120312101037.GA2459@pengutronix.de> References: <4F5DB793.3080904@linuxtv.org> <20120312101037.GA2459@pengutronix.de> Message-ID: <4F5DD28F.50600@linuxtv.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Wolfram, thank you for your answer. on 12.03.2012 11:10 Wolfram Sang said the following: >> Probably this is a question for the Freescale people: why was the >> "mx_sdhci" necessary at all > > It probably was never necessary, it was just easier to hack on a forked > driver, because you can't break other sdhci-users, I guess. Since large > portions of the code are duplicated but issues have been fixed in a > very, ahem, custom manner, this was never suitable for mainline. Back > then, most vendors thought this is good enough. Luckily, times have > changed a bit. Yes, I know that thinking. >> and why is it not necessary any more? > > Because I wanted SD support in mainline, so I had to take a different > path. I understand. >> Any help, hints and historical informations are highly appreciated, >> before I start to look deeper into this problem. > > They don't have a common ancestor. Just dig into both, you will > recognize patterns, I guess. Ok, to sum this up: SDIO IRQs are working in mx_sdhci in the Freescale tree because it was properly implemented and tested, obviously. SDIO IRQs are working for sdhci in mainline probably for other non-freescale platforms. You fixed the generic sdhci driver in mainline to work with iMX53 to get rid of the need for mx_sdhci, but probably never got the chance to test if SDIO IRQs are really working. That means, the subtle difference between mx_sdhci and sdhci to get SDIO IRQS to work on sdhci with iMX53 has yet to be found. > Regards, > Wolfram CU Michael.