From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752658AbcFVMhp (ORCPT ); Wed, 22 Jun 2016 08:37:45 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:37685 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752601AbcFVMhm (ORCPT ); Wed, 22 Jun 2016 08:37:42 -0400 MIME-Version: 1.0 In-Reply-To: <1465373996-2485-1-git-send-email-shawn.lin@rock-chips.com> References: <1465373996-2485-1-git-send-email-shawn.lin@rock-chips.com> From: Ulf Hansson Date: Wed, 22 Jun 2016 14:37:39 +0200 Message-ID: Subject: Re: [RFC PATCH 0/4] Introduce new caps to improve the card's init sequence To: Shawn Lin Cc: Jaehoon Chung , Rob Herring , linux-mmc , "linux-kernel@vger.kernel.org" , Doug Anderson , "open list:ARM/Rockchip SoC..." , "devicetree@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 8 June 2016 at 10:19, Shawn Lin wrote: > > Hi all, > > This patchset is gonna improve the card's init sequence > by exposing some caps to DT. > > The basic idea is to skip sending specific init cmd inspired > by Carlo Caione's commit[0]. > > To make it possible, I firstly expose Carlo's MMC_CAP2_NO_SDIO > to DT and extend two new caps for similar usage of sd and mmc. > We probably need it because for most of the boards, each of the > slots should have a specific function when designed. It's impossible > for one slot which can either to be used as eMMC or a SD card for a > given board. The same for SDIO case. > > We could have two ways to improve it > A) Skip sending specific commands if knowing we don't support > the specific card type. > B) Allow sending specific commands if knowing we do support > the specific card type. > > A) and B) shouldn't have difference, but I take A) as the final > one as it looks more consistent with Carlo's way, which does not > seem to break anything as possible. > > The only roadblock for this patchset to be landed should be the > improvement we gain from it. Theoretically sdio-card doesn't get > improvment as it's already in the first place to be attached. > But considering the sd and (e)MMC case, we should gain more benifit > from it. > > From the test, we can save nearly 2ms for attaching emmc against the > original 8ms. And we gain more than 30us improvement for sd card for > each insert. > > [0]: http://permalink.gmane.org/gmane.linux.kernel.mmc/34774 > > > > Shawn Lin (4): > Documentation: mmc: add description for new caps > mmc: core: expose MMC_CAP2_NO_SDIO to dt-binding > mmc: core: add cap-no-sd and cap-no-mmc properties > mmc: core: improve initialization flow > I would prefer that you restructure this series a bit. Start by adding each new MMC_CAP2* separately and without involving the DT parsing. Make the DT documentation patch come after the above, and add a new separate patch which exposes the caps to device tree. In that way, I can pick up the non DT parts and wait for Rob's ack/nack of the DT bindings. Kind regards Uffe > Documentation/devicetree/bindings/mmc/mmc.txt | 3 +++ > drivers/mmc/core/core.c | 10 +++++----- > drivers/mmc/core/host.c | 6 ++++++ > include/linux/mmc/host.h | 2 ++ > 4 files changed, 16 insertions(+), 5 deletions(-) > > -- > 2.3.7 > > > -- > 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