From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752559AbbJMIGi (ORCPT ); Tue, 13 Oct 2015 04:06:38 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:60120 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752121AbbJMIGb (ORCPT ); Tue, 13 Oct 2015 04:06:31 -0400 Subject: Re: [PATCH] mmc: omap_hsmmc: fix initialization order of mmc block devices To: References: <1444714193-24816-1-git-send-email-hs@denx.de> <561CA8D3.2090507@ti.com> <561CB653.5020707@denx.de> CC: , Arnd Bergmann , , Dirk Behme , , , Ulf Hansson , "Menon, Nishanth" From: Lokesh Vutla Message-ID: <561CBAE3.3020707@ti.com> Date: Tue, 13 Oct 2015 13:33:47 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <561CB653.5020707@denx.de> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tuesday 13 October 2015 01:14 PM, Heiko Schocher wrote: > Hello Lokesh, > > Am 13.10.2015 um 08:46 schrieb Lokesh Vutla: >> +Nishanth, >> >> On Tuesday 13 October 2015 10:59 AM, Heiko Schocher wrote: >>> On embedded devices, often there is a combination of >>> removable mmc devices (e.g. MMC/SD cards) and hard >>> wired ones (e.g. eMMC). Depending on the hardware >>> configuration, the 'mmcblkN' node might change if >>> the removable device is available or not at boot time. >>> >>> E.g. if the removable device is attached at boot time, >>> it might become mmxblk0. And the hard wired one mmcblk1. >>> But if the removable device isn't there at boot time, >>> the hard wired one will become mmcblk0. This makes it >>> somehow difficult to hard code the root device to the >>> non-removable device and boot fast. >> >> Why not use "root=PARTUUID=${uuid}" option instead of relying on >> mmcblk no? >> U-Boot can easily detect your partuuid. Refer to [1] on how TI platforms >> does this in u-boot. > > Good tip ... I do not know, if it is possible to update U-Boot > on this boards... > > Current U-Boot says: > U-Boot 2013.01.01_heads/master-gc7900a0 (2015-05-06 - 20:37:15) > > I2C: ready > DRAM: 512 MiB > [...] > U-Boot# mmc rescan > U-Boot# mmc part > > Partition Map for MMC device 0 -- Partition Type: DOS > > Part Start Sector Num Sectors UUID Type > 1 63 144522 000ce343-01 0e Boot > 2 144585 659861 000ce343-02 83 > U-Boot# part uuid mmc 0:2 uuid > Unknown command 'part' - try 'help' > U-Boot# > > So, if this patch has no chance for mainline, please let me > know it, thanks! > IIRC, Nishanth had posted a patch something similar but got rejected for some reason. Probably Nishanth can comment more here. Thanks and regards, Lokesh