From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail.kymetacorp.com ([192.81.58.21]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZxJVD-0006bi-EW for barebox@lists.infradead.org; Fri, 13 Nov 2015 18:56:18 +0000 From: Trent Piepho Date: Fri, 13 Nov 2015 18:54:14 +0000 Message-ID: <1447440856.4553.139.camel@rtred1test09.kymeta.local> References: <1447374984.4553.133.camel@rtred1test09.kymeta.local> <20151113102851.GF8526@pengutronix.de> In-Reply-To: <20151113102851.GF8526@pengutronix.de> Content-Language: en-US Content-ID: MIME-Version: 1.0 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: MCI bus-width host caps via device tree don't work properly for dw and imx To: Sascha Hauer Cc: barebox On Fri, 2015-11-13 at 11:28 +0100, Sascha Hauer wrote: > > The mci_of_parse call will not remove the 4 and 8 bits caps. There is > > the same problem in imx-esdhc.c. The other two users of mci_of_parse, > > mxs.c and tegra-sdmmc.c, don't have this problem, since they don't set > > any bus-width host_caps in the driver and depend on the DT or > > platform_data to have this info. > > > > With drivers split 50/50, which is the right way? Don't have the driver > > report what bits it supports and depend on the device tree to have that > > information? Or have of_mci_parse remove widths that aren't indicated > > as supported in the DT, so that the DT can remove widths the hardware > > indicates it supports. > > I think the resulting flags should be the subset of what all components > can do, that is (driver_flags & devicetree_flags & card_flags). > > So mci_of_parse() should IMO clear the MMC_CAP_8_BIT_DATA flag if the > bus-width property is set to 4. > > You should encounter the same problem under Linux, right? Don't have the problem on Linux. The OF parsing works the same way, but the dw driver stats with 0 bus-width caps, like how mxs and tegra-sdmmc work. The linux dw_mmc driver allows "sub-drivers" to supply caps, and the Exynos4/5 driver adds CAP_8_BIT. Which is probably broken, as it doesn't add 4_BIT as well and will have the same problem with the device tree not being able to remove bus widths. _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox