From patchwork Wed Jul 10 15:42:02 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 2825767 Return-Path: X-Original-To: patchwork-linux-mmc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 61744C0AB2 for ; Wed, 10 Jul 2013 15:42:20 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 28DC520198 for ; Wed, 10 Jul 2013 15:42:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E2DAA20187 for ; Wed, 10 Jul 2013 15:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754733Ab3GJPmQ (ORCPT ); Wed, 10 Jul 2013 11:42:16 -0400 Received: from mail-ve0-f202.google.com ([209.85.128.202]:39036 "EHLO mail-ve0-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754457Ab3GJPmP (ORCPT ); Wed, 10 Jul 2013 11:42:15 -0400 Received: by mail-ve0-f202.google.com with SMTP id m1so623209ves.1 for ; Wed, 10 Jul 2013 08:42:14 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references :x-gm-message-state; bh=K5lMbwZkVczoRDISZfNM6A+UOetz3dWMVk2kp2Bcqfo=; b=Tz4zvERHwymb4p+JaAVvPLsOL2xuDNIZna2MF3sOQFlR40XtA0VlmxkTn0glVhET46 DZnT+/S7p4npSrwQnfrczz3HM6uflL8YMX/XdYsZnS6ILabyL8tMG53Tx2MrY2y3QEJ/ ucMqr5lr054y3LTQz5usc0y0of9UIThXLNm4Ky/aOPZvbP0DIBtd+yB/N2zdrbE0tuXp 6YjMNys7OhPdjKM26XzvzfduTpdIVwYv8V+1cDpmZPOfhtkhnWH7u8gYEy3h18c15oDA oy5CR2MgEzZdFPjl67FS3vPYvCdir/3QYfLJBfKJ+zzyN2y9UcFIQqORW4lfIGlwkEnv UU5g== X-Received: by 10.236.226.6 with SMTP id a6mr17901886yhq.35.1373470934551; Wed, 10 Jul 2013 08:42:14 -0700 (PDT) Received: from corp2gmr1-1.hot.corp.google.com (corp2gmr1-1.hot.corp.google.com [172.24.189.92]) by gmr-mx.google.com with ESMTPS id o24si1909880yhm.1.2013.07.10.08.42.14 for (version=TLSv1.1 cipher=AES128-SHA bits=128/128); Wed, 10 Jul 2013 08:42:14 -0700 (PDT) Received: from tictac.mtv.corp.google.com (tictac.mtv.corp.google.com [172.22.162.34]) by corp2gmr1-1.hot.corp.google.com (Postfix) with ESMTP id 62C2031C0F6; Wed, 10 Jul 2013 08:42:14 -0700 (PDT) Received: by tictac.mtv.corp.google.com (Postfix, from userid 121310) id 1571080693; Wed, 10 Jul 2013 08:42:14 -0700 (PDT) From: Doug Anderson To: Chris Ball Cc: Olof Johansson , Jaehoon Chung , Seungwon Jeon , James Hogan , Grant Grundler , Alim Akhtar , Abhilash Kesavan , Tomasz Figa , Doug Anderson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 1/5] mmc: dw_mmc: Invalidate cache of current_speed after suspend/resume Date: Wed, 10 Jul 2013 08:42:02 -0700 Message-Id: <1373470926-19314-2-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 1.8.3 In-Reply-To: <1373470926-19314-1-git-send-email-dianders@chromium.org> References: <1373411961-23812-1-git-send-email-dianders@chromium.org> <1373470926-19314-1-git-send-email-dianders@chromium.org> X-Gm-Message-State: ALoCoQmtjBT309+fQnOAeJieZswV/uE5xtu4OEgLMx34R8tGJykMSI3SFOT5+b91BU/tLCYE8PVkXpYPO5W3rFKTyglFukG+scLqdM5c6zZkZJ36MEsS2DidNmOCSP/HBF8N5MOgoC+6kC5cO0kdORtwj8LVlGVwK7+2xPhchdpOxM0McDgFlwRiEiDo486uXEHzjAvw5kmEievswTbwir95UJCKwVDYXw== Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Spam-Status: No, score=-7.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The dw_mmc driver keeps a cache of the current slot->clock in order to avoid doing a whole lot of work every time set_ios() is called. However, after suspend/resume the register values are bogus so we need to ensure that the cached value is invalidated. In many cases we got by without this since the core mmc code fiddles with the clock a lot. If we've got a card present we're probably running it at something like 50MHz and the core will temporarily switch us to 400kHz after resume. One case that didn't work (for me) is the case of having no card in the slot. The slot is initted to 400kHz at boot time. After suspend/resume the slot thinks it's still at 400kHz (due to the cache) so doesn't adjust timing. When it tries to send the command at probe time it just times out and gets left in a bad state. Invalidating the current_speed also means that we don't need to call: dw_mci_setup_bus(slot, true); ...to force an update of the clock in the case when the slot was left powered. Signed-off-by: Doug Anderson --- Changes in v3: None Changes in v2: - Fix typo (some -> come) - Use ~0 instead of 0xFFFFFFFF; add comment about value drivers/mmc/host/dw_mmc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index bc3a1bc..7a5ce6a 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -2488,13 +2488,19 @@ int dw_mci_resume(struct dw_mci *host) DW_MCI_ERROR_FLAGS | SDMMC_INT_CD); mci_writel(host, CTRL, SDMMC_CTRL_INT_ENABLE); + /* + * Invalidate the 'current_speed' value since CLKDIV has come up in + * default state and our cache is incorrect; set to something we know + * slot->clock won't be. + */ + host->current_speed = ~0; + for (i = 0; i < host->num_slots; i++) { struct dw_mci_slot *slot = host->slot[i]; if (!slot) continue; if (slot->mmc->pm_flags & MMC_PM_KEEP_POWER) { dw_mci_set_ios(slot->mmc, &slot->mmc->ios); - dw_mci_setup_bus(slot, true); } ret = mmc_resume_host(host->slot[i]->mmc);