From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755928AbdJLULu (ORCPT ); Thu, 12 Oct 2017 16:11:50 -0400 Received: from mail-pf0-f171.google.com ([209.85.192.171]:54772 "EHLO mail-pf0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755717AbdJLULo (ORCPT ); Thu, 12 Oct 2017 16:11:44 -0400 X-Google-Smtp-Source: AOwi7QDVV84EFfD7Erqnw4car3s6ZUmpDS83vBc2/4Roq2MJ7ei75i8DbddPfnU4jcq+sqfpizAd0A== 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 4/5] mmc: dw_mmc: Fix the DTO timeout calculation Date: Thu, 12 Oct 2017 13:11:17 -0700 Message-Id: <20171012201118.23570-5-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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Just like the CTO timeout calculation introduced recently, the DTO timeout calculation was incorrect. 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: This was likely not terribly important until commit 16a34574c6ca ("mmc: dw_mmc: remove the quirks flags") landed because "DIV" is documented on Rockchip SoCs (the ones that used to define the quirk) to always be 0 or 1. ...and, in fact, it's documented to only be 1 with EMMC in 8-bit DDR52 mode. Thus before the quirk was applied to everyone it was mostly OK to ignore the DIV value. I haven't personally observed any problems that are fixed by this patch but I also haven't tested this anywhere with a DIV other an 0. AKA: this problem was found simply by code inspection and I have no failing test cases that are fixed by it. Presumably this could fix real bugs for someone out there, though. Fixes: 16a34574c6ca ("mmc: dw_mmc: remove the quirks flags") Signed-off-by: Douglas Anderson --- Changes in v2: - Fix the DTO timeout calculation new for v2 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 50148991f30e..6bc87b1385a9 100644 --- a/drivers/mmc/host/dw_mmc.c +++ b/drivers/mmc/host/dw_mmc.c @@ -1936,10 +1936,16 @@ static int dw_mci_data_complete(struct dw_mci *host, struct mmc_data *data) static void dw_mci_set_drto(struct dw_mci *host) { unsigned int drto_clks; + unsigned int drto_div; unsigned int drto_ms; + unsigned long irqflags; drto_clks = mci_readl(host, TMOUT) >> 8; - drto_ms = DIV_ROUND_UP(drto_clks, host->bus_hz / 1000); + drto_div = (mci_readl(host, CLKDIV) & 0xff) * 2; + if (drto_div == 0) + drto_div = 1; + drto_ms = DIV_ROUND_UP(MSEC_PER_SEC * drto_clks * drto_div, + host->bus_hz); /* add a bit spare time */ drto_ms += 10; -- 2.15.0.rc0.271.g36b669edcc-goog