Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754662AbbHLMyY (ORCPT ); Wed, 12 Aug 2015 08:54:24 -0400 Received: from mail-wi0-f169.google.com ([209.85.212.169]:35392 "EHLO mail-wi0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751898AbbHLMyX (ORCPT ); Wed, 12 Aug 2015 08:54:23 -0400 MIME-Version: 1.0 In-Reply-To: <55CB3D92.6040403@redhat.com> References: <55CB3D92.6040403@redhat.com> From: Michal Suchanek Date: Wed, 12 Aug 2015 14:53:42 +0200 Message-ID: Subject: Re: [linux-sunxi] [PATCH 3/3] mmc: sunxi: use controller automatic clock gating. To: Hans de Goede Cc: linux-sunxi , Seungwon Jeon , Jaehoon Chung , Ulf Hansson , Maxime Ripard , =?UTF-8?Q?David_Lanzend=C3=B6rfer?= , Chen-Yu Tsai , Arnd Bergmann , linux-mmc , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.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 Content-Length: 1426 Lines: 46 On 12 August 2015 at 14:35, Hans de Goede wrote: > Hi, > > On 12-08-15 14:23, Michal Suchanek wrote: >> >> When core does not set the MMC_QUIRK_BROKEN_CLK_GATING flag enable >> automatic hardware controlled clock gating on the mmc interface. >> >> Signed-off-by: Michal Suchanek > > > In general this looks good, but I wonder how intensively this has > been tested ? Unlike the wrong timeout it does not cause the boards to crash frequently ;-) It would be nice if somebody actively using some board atm tested this. > Also given the long latencies when using manual > clock on/off support, have you done any testing to check what I suspect the long latency is due to the controller flushing data to the card or something like that since it happens only under load. > sort of latencies this adds, e.g. Both with and without > the patch, dump all the filesystem caches: > > echo 3 > /proc/sys/vm/drop_caches > > And then do: > > time cat /some/small/file/on/the/sdcard > > Do this at least 3 time both with and without the patch, and see > if there are any noticable differences ? Yes, it would be good idea to test. Thanks Michal -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/