From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.92.2 #3 (Red Hat Linux)) id 1iF12M-0007yf-A1 for barebox@lists.infradead.org; Mon, 30 Sep 2019 19:08:47 +0000 Date: Mon, 30 Sep 2019 21:08:42 +0200 From: Sascha Hauer Message-ID: <20190930190842.zuxu6lt6tqnbe3pn@pengutronix.de> References: <20190930080748.29977-1-andrew.smirnov@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190930080748.29977-1-andrew.smirnov@gmail.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH] mci: imx-esdhc-pbl: Fix watermark level value for i.MX To: Andrey Smirnov Cc: barebox@lists.infradead.org, Chris Healy , Ruslan Sushko On Mon, Sep 30, 2019 at 01:07:48AM -0700, Andrey Smirnov wrote: > Layerscape and i.MX have different semantics of Watermark Level > Register. Whereas the former uses "0" to signify maximum allowed > value, the latter does not. > > According to the RM (i.MX8MQ, i.MX6): > > "...The read burst length must be less than or equal to the read > watermark level.." > > Setting Watermark Level Register to zero violates that limitation. It > appears that, on i.MX8MQ, not following that rule causes certain > configs + toolchains to result in non-bootable image. Specifically, > polling for CICHB, CIDHB and DLA to clear in esdhc_send_cmd() times > out. There doesn't appear to be any clear relationship as to what kind > of image will have the problem, but the following combinations failed > to boot on ZII i.MX8MQ Zest board: > > - gcc version 9.2.1 20190827 (Red Hat Cross 9.2.1-1) (GCC) + > imx_v8_defconfig + CONFIG_DEBUG_LL and CONFIG_PBL_CONSOLE > > - gcc version 5.5.0 (Timesys 20190405) (custom toolchain) + > imx_v8_defconfig > > Setting WML's *_BRST_LE to 16 and *_WML to 128 on i.MX resolves the > issue (same setting that's selected by writing 0 on Layerscape). > > Fixes: 48562aeaa8 ("esdhc-xload: check for PRSSTAT_BREN only after each block") > Cc: Chris Healy > Cc: Ruslan Sushko > Signed-off-by: Andrey Smirnov > --- > > Sascha: > > I don't have a very good explanation as to why those particuar > toolchain + config settings cause problems and it's not clear how the > IP block interprets those illegal values since RM is silent on that. I > spent a solid chunk of time trying to figure that out without much > luck, so I figured that maybe, given that mismatch is pretty clear > from comparing two datasheets, this fix can go in without having one. > > If this patch is a acceptable, I think it should also go to master > since it fixes boot break I checked both reference manuals and it's clear that we do the wrong thing on i.MX currently, so I am fine with the patch. It seems that you have forgotten to set wrap_wml to 1 for layerscape though. Regards Sascha -- 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 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox