From patchwork Thu Oct 12 20:11:15 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 10002775 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 075CD60216 for ; Thu, 12 Oct 2017 20:13:23 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ED07B28E98 for ; Thu, 12 Oct 2017 20:13:22 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E1DAF28EA0; Thu, 12 Oct 2017 20:13:22 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID,URIBL_BLACK autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6C35F28E98 for ; Thu, 12 Oct 2017 20:13:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755639AbdJLULn (ORCPT ); Thu, 12 Oct 2017 16:11:43 -0400 Received: from mail-pf0-f169.google.com ([209.85.192.169]:43406 "EHLO mail-pf0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755573AbdJLULl (ORCPT ); Thu, 12 Oct 2017 16:11:41 -0400 Received: by mail-pf0-f169.google.com with SMTP id a8so6001657pfc.0 for ; Thu, 12 Oct 2017 13:11:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=q3PwirLEh7wNr9Na9wkG9qQNUz76d5FHfTOhTEY9VjU=; b=LU7anlOp6C2mebudlqos+q/psN0S9hKij4QihU5B9YXuFfd+TUlrGKCNdvY5VH+TTi Yjr0RrnxZ6RbclgtGw00Ph9ZCdGBS983hYnEKjv6rrps8oITTv18ceSGDA5syA+gyF1f Wriu558kIRtT6Wn3akEJDJDUXrg0UhCUxItrQ= 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:in-reply-to :references; bh=q3PwirLEh7wNr9Na9wkG9qQNUz76d5FHfTOhTEY9VjU=; b=nTtJ8EgC2k9HmwzDU3tO7+TD6HVqjjKduIwIaIzJDjoD9RDM1tgVRcYkGRyXkOh1uB MlSyUp5RUOW7kx126+eUtBwrieTP9bXj6HLh3wjVp7UF5J4Kyye669WisX3vo55yCwt4 j9czV9GiCNToCx8cIK8iKk8w4VPvcv+NXyVeHvCcLeOu0HR0eSU+E+Mn/0vQCigPcTSM TGGu7a0pts5eomTM0fiRnr827PSeoqWDRugHaWjLrya/TT3R9B58vxsxa7gvwhe+jXmP M9sVW1txFXHERFrDWb4AP7ieB8XSW+Jet890V9bBFEuVyGC3SbhNGeVJ6e9wkTkcRbdW KjRA== X-Gm-Message-State: AMCzsaVmXWU00yHSGWBQBGunb6dl2pP7EfyWyEfmTlZbPf63yOTj7IbL C0+7ZHb5ODpS3mquG5mBKnbQ7Q== X-Google-Smtp-Source: AOwi7QDoqLfYuf0uLXTcB5b9DrtvXYUel2BuExuHqPlwh0RiKn7ewZR07y0mjKknr0nLDLY+8YQQkQ== X-Received: by 10.98.67.217 with SMTP id l86mr3135524pfi.92.1507839101216; Thu, 12 Oct 2017 13:11:41 -0700 (PDT) Received: from tictac.mtv.corp.google.com ([172.22.112.154]) by smtp.gmail.com with ESMTPSA id l3sm29749635pgn.36.2017.10.12.13.11.39 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 12 Oct 2017 13:11:40 -0700 (PDT) From: Douglas Anderson To: jh80.chung@samsung.com, ulf.hansson@linaro.org, shawn.lin@rock-chips.com Cc: xzy.xu@rock-chips.com, amstan@chromium.org, linux-rockchip@lists.infradead.org, briannorris@chromium.org, linux-samsung-soc@vger.kernel.org, kernel@esmil.dk, Douglas Anderson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v2 2/5] mmc: dw_mmc: Fix the CTO timeout calculation Date: Thu, 12 Oct 2017 13:11:15 -0700 Message-Id: <20171012201118.23570-3-dianders@chromium.org> X-Mailer: git-send-email 2.15.0.rc0.271.g36b669edcc-goog In-Reply-To: <20171012201118.23570-1-dianders@chromium.org> References: <20171012201118.23570-1-dianders@chromium.org> Sender: linux-mmc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mmc@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In the commit 03de19212ea3 ("mmc: dw_mmc: introduce timer for broken command transfer over scheme") we tried to calculate the expected hardware command timeout value. Unfortunately that calculation isn't quite correct in all cases. It used "bus_hz" but, as far as I can tell, it's supposed to use the card clock. Let's account for the div value, which is documented as 2x the value stored in the register, or 1 if the register is 0. NOTE: It's not expected that this will actually fix anything important since the 10 ms margin added by the function will pretty much dwarf any calculations. The card clock should be 100 kHz at minimum and: 1000 ms/s * (255 * 2) / 100000 Hz. Gives us 5.1 ms. ...so really the point of this patch is just to make the code more "correct" in case anyone ever tries to remove the 10 ms buffer. Fixes: 03de19212ea3 ("mmc: dw_mmc: introduce timer for broken command transfer over scheme") Tested-by: Emil Renner Berthing Reviewed-by: Shawn Lin Signed-off-by: Douglas Anderson --- Changes in v2: None drivers/mmc/host/dw_mmc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c index f5b2bb4b4d98..16516c528a88 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -401,10 +401,14 @@ static u32 dw_mci_prep_stop_abort(struct dw_mci *host, struct mmc_command *cmd) static inline void dw_mci_set_cto(struct dw_mci *host) { unsigned int cto_clks; + unsigned int cto_div; unsigned int cto_ms; cto_clks = mci_readl(host, TMOUT) & 0xff; - cto_ms = DIV_ROUND_UP(cto_clks, host->bus_hz / 1000); + cto_div = (mci_readl(host, CLKDIV) & 0xff) * 2; + if (cto_div == 0) + cto_div = 1; + cto_ms = DIV_ROUND_UP(MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz); /* add a bit spare time */ cto_ms += 10;