From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steffen Trumtrar Subject: Re: [BUG/RFC] SDHCI_QUIRK_NO_MULTIBLOCK for i.MX35/25 Date: Tue, 17 Dec 2013 10:28:30 +0100 Message-ID: <20131217092830.GM25478@pengutronix.de> References: <20131115091537.GF28658@pengutronix.de> <20131202085806.GF25308@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:54431 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750949Ab3LQJ2c (ORCPT ); Tue, 17 Dec 2013 04:28:32 -0500 Content-Disposition: inline In-Reply-To: <20131202085806.GF25308@pengutronix.de> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: linux-mmc@vger.kernel.org Cc: Chris Ball On Mon, Dec 02, 2013 at 09:58:06AM +0100, Steffen Trumtrar wrote: > On Fri, Nov 15, 2013 at 10:15:37AM +0100, Steffen Trumtrar wrote: > > Hi! > > > > > > 1 Actual Use-Case > > ================= > > > > I have a SDIO card with a Marvell 8787, that works fine on an i.MX53 > > with the drivers/net/wireless/mwifiex/sdio.c driver. On an i.MX35 > > however the loading of the firmware errors out on the very first > > single-block transfer with 1024 bytes payload. > > > > > > 2 Reason for failure > > ==================== > > > > sdhci defines SDHCI_QUIRK_NO_MULTIBLOCK to completely disable > > multi-block transfers for a host. The max_blk_count is simply set to 1 > > to achieve this. Currently only i.MX35 and i.MX25 seem to be the only > > users of that quirk. The quirk is used to fix an errata on these > > SoCs, that says, that "CMD12 abort operation does not abort data > > transfer on AHB". (ENGcm07207) > > > > So, this is a problem regarding only SD and not SDIO. On this special > > SDIO card, it looks like multi-block transfer has to be used for > > anything >16 bytes. Removing the quirk fixes the firmware loading > > error. The device is detected successfully after loading and can > > connect to an AP. > > > > > > 3 Question > > ========== > > > > And here comes the question: What would be the correct approach to fix > > that and differentiate those two cases, so that we can use multi-block > > transfers with CMD53 but not with CMD25(?!) ? > > > > 1a. As I see no other users of that quirk, it might be okay to rename > > it, to better reflect the actual problem it fixes (broken CMD12 or > > something). > > > > 1b. When the host knows with what it deals with (SDIO or SD) set the > > max_blk_count according to the quirk. And only in the SD case, that is. > > > > or > > > > 2. Introduce a max_blk_count_sd and max_blk_count_sdio and use them > > everywhere. Seems rather invasive and over the top. > > > > or > > > > 3. something better. > > > > > > Ping... > Ping ping ... Regards, Steffen -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |