Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755462AbcDBAXm (ORCPT ); Fri, 1 Apr 2016 20:23:42 -0400 Received: from mail-lb0-f173.google.com ([209.85.217.173]:36116 "EHLO mail-lb0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753633AbcDBAXk (ORCPT ); Fri, 1 Apr 2016 20:23:40 -0400 MIME-Version: 1.0 In-Reply-To: References: <1447426572-11756-1-git-send-email-holgerschurig@gmail.com> <87r3ierjae.fsf@gmail.com> From: Gwendal Grignou Date: Fri, 1 Apr 2016 17:23:19 -0700 X-Google-Sender-Auth: kaAleHGVS52D0TSGlGSPf4eWDrY Message-ID: Subject: Re: [RFC 0/6] mmc: Field Firmware Update To: Ulf Hansson Cc: Alex Lemberg , Holger Schurig , Avi Shchislowski , "linux-mmc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Chris Ball , Baolin Wang Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3001 Lines: 69 On Thu, Jan 14, 2016 at 5:16 AM, Ulf Hansson wrote: > On 28 December 2015 at 15:12, Alex Lemberg wrote: >> Hi Ulf, >> >> We succeeded to run FFU via new mmc multi-command ioctl without any code modification, >> but only by using Single Sector commands (CMD24). >> >> From running the FFU and from code review, we see two minor issues in this way of running FFU: >> 1. There is no support for Multiple Block write commands (CMD25) in existing IOCTL implementation - > > That's right. But I guess we cope without the multiple block support!? > > Although, I wonder how hard it would be to add it... > >> seems like there is no polling for the card status on data transfer completion. > > We should fix that! > > In the rpmb case, we check the status so we can probably trigger that > code to run for CMD24/25 as well. > >> (The kernel FFU implementation supports FFU using Multiple Block Write commands). >> 2. As you probably remember, there are two ways to install the new FW in the end of FFU process - >> In case MODE_OPERATION_CODES field is not supported by the device, the host sets to NORMAL state > > Before starting the update, you can find out which mode that is > supported and take relevant actions, right? > >> and initiates a CMD0/HW_Reset/Power cycle to install the new firmware. > > Yes, but that's fragile - as discussed earlier. > > What we really need to do is to also remove the "card" device from the > system, as otherwise we may have invalid data in its member variables > and who knows what issues that can cause to upper levels. > >> This sequence cannot be done via multi-command ioctl, and requires manual reset of the device/platform. > > Yepp, it seems so at least for now. Perhaps we can think of a way to > improve this? > >> (The kernel FFU implementation supports both FW install methods). >> >> For running FFU via new mmc multi-command ioctl, we have modified mmc-utils and add new functionality for FFU. >> Please let us know if you want us to submit the patch for mmc-utils FFU functionality via multi-command ioctl. > > Yes please. Don't forget to send this to Chris as well! I am arriving after the battle, but I have finally rebased the eMMC FFU kernel ffu code to 4.x. It is based on what Avi and Alex have written. As stated earlier, the advantage over using MMC_MUTLI_CMD is we can force a reset and rescan of the card without asking the user to reboot their machine. Also, by only sending a firmware name over the ioctl, we can use Kees' work for firmware validation (https://lwn.net/Articles/605432/). To prevent downloading firmware from unknown source, we would reject some commands (like SWITCH with FFU_MODE) in the kernel MMC_IOC/MULTI_CMD ioctl handler. Gwendal. > > [...] > > Kind regards > Uffe > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html