From patchwork Thu Dec 10 21:27:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 11966565 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 920A6C0018C for ; Thu, 10 Dec 2020 21:28:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5182F23D9A for ; Thu, 10 Dec 2020 21:28:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404771AbgLJV2n (ORCPT ); Thu, 10 Dec 2020 16:28:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41366 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405012AbgLJV2m (ORCPT ); Thu, 10 Dec 2020 16:28:42 -0500 Received: from mail-pf1-x442.google.com (mail-pf1-x442.google.com [IPv6:2607:f8b0:4864:20::442]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9A6DFC061794 for ; Thu, 10 Dec 2020 13:28:01 -0800 (PST) Received: by mail-pf1-x442.google.com with SMTP id t8so5356373pfg.8 for ; Thu, 10 Dec 2020 13:28:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=FbWegn4ZcYaOlGOVRUV3EeXBEpEFCkkB7Ag5Ofeu968=; b=SOzaztliM9aHIQCbuNc7tHYRK9V3tX/XLLl1LEJ4fIxE7wPsAS8CsdXJYlh0S13KWQ 8KisfIcHujOla0iGv0LAFHNCNwxM/Ws/De86QeLZGN+wucsFQgDLoIk3YHIm41TKmu0C BqMiTBQsX7SKnFeqF+FcmlUUph401+ogRljFw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=FbWegn4ZcYaOlGOVRUV3EeXBEpEFCkkB7Ag5Ofeu968=; b=YZD5CxGB1X2zzP0V7FK5CeG4Engx//491OI3JaTTdA/FWxYIvEhRIko+2+8TrPKfjF 6ThFZ1DDHJ9UOWzTWr884yc4h0h5GSO1vabYPeBRxPKunv7TOetDO6LKGJSW7tiVnzhE rsN7y8XPVgzrUc9iVYHWgRsYi4xZluaPJ22YTXMV6GZqat+trk4gTuCISB/dQBj6+cBc Xy19apo1huqwGdXmYiaqWqj/apxvPYo14x+BWAe5DgU6/Expm0oKOKl9vMI9dlOeN2+s 4hmN8b+eHIvGCYfQ+vu7xsOoZ+4ud1swaJG8PamCg45+6/rblcAY0mMUvauyUkRALQaX mpHw== X-Gm-Message-State: AOAM531XAw8Q+wcNJ4EYSHM+rYSstvnrXAb6iajJO0UELCqgPZp5w1NR vHYzJXalXhqf8ph+IUKLhE7yQw== X-Google-Smtp-Source: ABdhPJx0GJXBr9wuxbpn/W7p5P5fmbFCWAp+gJEv/NSPZ3pFUeZWY5JQNddQzAXwm6eheATdbJV2Jg== X-Received: by 2002:a17:90a:fb97:: with SMTP id cp23mr9796208pjb.215.1607635681045; Thu, 10 Dec 2020 13:28:01 -0800 (PST) Received: from tictac2.mtv.corp.google.com ([2620:15c:202:1:42b0:34ff:fe3d:58e6]) by smtp.gmail.com with ESMTPSA id t19sm7901664pgk.86.2020.12.10.13.27.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Dec 2020 13:28:00 -0800 (PST) From: Douglas Anderson To: Ulf Hansson , Adrian Hunter Cc: Stephen Boyd , vbadigan@codeaurora.org, Taniya Das , Douglas Anderson , Andy Gross , Bjorn Andersson , linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org Subject: [PATCH v3] mmc: sdhci-msm: Warn about overclocking SD/MMC Date: Thu, 10 Dec 2020 13:27:52 -0800 Message-Id: <20201210132745.v3.1.Iec3430c7d3c2a29262695edef7b82a14aaa567e5@changeid> X-Mailer: git-send-email 2.29.2.576.ga3fc446d84-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org As talked about in commit 5e4b7e82d497 ("clk: qcom: gcc-sdm845: Use floor ops for sdcc clks"), most clocks handled by the Qualcomm clock drivers are rounded _up_ by default instead of down. We should make sure SD/MMC clocks are always rounded down in the clock drivers. Let's add a warning in the Qualcomm SDHCI driver to help catch the problem. This would have saved a bunch of time [1]. [1] http://lore.kernel.org/r/20201210102234.1.I096779f219625148900fc984dd0084ed1ba87c7f@changeid Suggested-by: Stephen Boyd Signed-off-by: Douglas Anderson Reviewed-by: Stephen Boyd Reviewed-by: Bjorn Andersson --- Changes in v3: - Proper printf format code. Changes in v2: - Store rate in unsigned long, not unsigned int. - Reuse the clk_get_rate() in the later print. drivers/mmc/host/sdhci-msm.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c index 3451eb325513..50beb407dbe9 100644 --- a/drivers/mmc/host/sdhci-msm.c +++ b/drivers/mmc/host/sdhci-msm.c @@ -353,6 +353,7 @@ static void msm_set_clock_rate_for_bus_mode(struct sdhci_host *host, struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host); struct mmc_ios curr_ios = host->mmc->ios; struct clk *core_clk = msm_host->bulk_clks[0].clk; + unsigned long achieved_rate; int rc; clock = msm_get_clock_rate_for_bus_mode(host, clock); @@ -363,10 +364,20 @@ static void msm_set_clock_rate_for_bus_mode(struct sdhci_host *host, curr_ios.timing); return; } + + /* + * Qualcomm clock drivers by default round clock _up_ if they can't + * make the requested rate. This is not good for SD. Yell if we + * encounter it. + */ + achieved_rate = clk_get_rate(core_clk); + if (achieved_rate > clock) + pr_warn("%s: Card appears overclocked; req %u Hz, actual %lu Hz\n", + mmc_hostname(host->mmc), clock, achieved_rate); + msm_host->clk_rate = clock; pr_debug("%s: Setting clock at rate %lu at timing %d\n", - mmc_hostname(host->mmc), clk_get_rate(core_clk), - curr_ios.timing); + mmc_hostname(host->mmc), achieved_rate, curr_ios.timing); } /* Platform specific tuning */