Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753053AbbBYSWs (ORCPT ); Wed, 25 Feb 2015 13:22:48 -0500 Received: from bhuna.collabora.co.uk ([93.93.135.160]:52264 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752503AbbBYSWq (ORCPT ); Wed, 25 Feb 2015 13:22:46 -0500 Message-ID: <54EE12EF.20607@collabora.co.uk> Date: Wed, 25 Feb 2015 19:22:39 +0100 From: Javier Martinez Canillas User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.2.0 MIME-Version: 1.0 To: Doug Anderson , Jaehoon Chung , Seungwon Jeon , Ulf Hansson CC: Alim Akhtar , Sonny Rao , Andrew Bresticker , Heiko Stuebner , Addy Ke , Alexandru Stan , chris@printf.net, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] mmc: dw_mmc: Don't start commands while busy References: <1424464316-4397-1-git-send-email-dianders@chromium.org> In-Reply-To: <1424464316-4397-1-git-send-email-dianders@chromium.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1261 Lines: 33 Hello Doug, On 02/20/2015 09:31 PM, Doug Anderson wrote: > We've seen problems on some WiFi modules where we seem to send a CMD53 > (which requires the data lines) while the module is asserting busy. > We shouldn't do that. > > The Designware Databook says that before issuing a new data transfer > command we should check for busy, so that's what we'll do. > > We'll leverage the existing dw_mmc knowledge about whether it should > wait for the previous command to finish to know whether we should > check for busy before sending the command. This means we won't end up > incorrectly waiting for things like CMD52 (SDIO) or CMD13 (SD) which > don't use the data line. > > Note that this also has the advantage of making sure that we don't > change the clock while the card is busy, too. > > Signed-off-by: Doug Anderson > On an Exynos5250 Snow, Exynos5420 Peach Pit and Exynos5800 Peach Pi: Tested-by: Javier Martinez Canillas Best regards, Javier -- 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/