From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jisheng Zhang Subject: Re: [PATCH v4] mmc: dw_mmc: Fix the DTO/CTO timeout overflow calculation for 32-bit systems Date: Thu, 1 Mar 2018 13:57:55 +0800 Message-ID: <20180301135755.7e26f12e@xhacker.debian> References: <20180228115318.20154-1-Evgeniy.Didin@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20180228115318.20154-1-Evgeniy.Didin@synopsys.com> Sender: linux-kernel-owner@vger.kernel.org To: Evgeniy Didin , Jaehoon Chung Cc: linux-mmc@vger.kernel.org, Alexey Brodkin , Eugeniy Paltsev , Douglas Anderson , Ulf Hansson , Andy Shevchenko , Shawn Lin , Vineet Gupta , linux-kernel@vger.kernel.org, linux-snps-arc@lists.infradead.org, stable@vger.kernel.org List-Id: linux-mmc@vger.kernel.org On Wed, 28 Feb 2018 14:53:18 +0300 Evgeniy Didin wrote: > In commit 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation") and > commit 4c2357f57dd5 ("mmc: dw_mmc: Fix the CTO timeout calculation") > have been made changes which cause multiply overflow for 32-bit systems. > The broken timeout calculations leads to unexpected ETIMEDOUT errors and > causes stacktrace splat (such as below) during normal data exchange > with SD-card. > > | Running : 4M-check-reassembly-tcp-cmykw2-rotatew2.out -v0 -w1 > | - Info: Finished target initialization. > | mmcblk0: error -110 transferring data, sector 320544, nr 2048, cmd response > | 0x900, card status 0x0 > > DIV_ROUND_UP_ULL helps to escape usage of __udivdi3() from libgcc and so > code gets compiled on all 32-bit platforms as opposed to usage > of DIV_ROUND_UP when we may only compile stuff on a very few arches. > > Lets cast this multiply to u64 type which prevents overflow. Reviewed-by: Jisheng Zhang > > Tested-by: Vineet Gupta > Reported-by: Vineet Gupta # ARC STAR 9001306872 HSDK, sdio: board crashes when copying big files > Fixes: 9d9491a7da2a ("mmc: dw_mmc: Fix the DTO timeout calculation") > Fixes: 4c2357f57dd5 ("mmc: dw_mmc: Fix the CTO timeout calculation") > > Signed-off-by: Evgeniy Didin > > CC: Alexey Brodkin > CC: Eugeniy Paltsev > CC: Douglas Anderson > CC: Ulf Hansson > CC: Andy Shevchenko > CC: Jisheng Zhang > CC: Shawn Lin > CC: Vineet Gupta > CC: linux-kernel@vger.kernel.org > CC: linux-snps-arc@lists.infradead.org > Cc: > --- > Changes since v3: > -Switch DIV_ROUND_UP macro to DIV_ROUND_UP_ULL > -Make one patch from two patches > -Modify commit message > > Changes sinve v2: > -add fix for cto_ms > > Changes since v1: > -uint64_t switched to u64 > > drivers/mmc/host/dw_mmc.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 0aa39975f33b..cba534d4c81b 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -409,7 +409,9 @@ static inline void dw_mci_set_cto(struct dw_mci *host) > 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); > + > + cto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * cto_clks * cto_div, > + host->bus_hz); > > /* add a bit spare time */ > cto_ms += 10; > @@ -1944,8 +1946,9 @@ static void dw_mci_set_drto(struct dw_mci *host) > 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); > + > + drto_ms = DIV_ROUND_UP_ULL((u64)MSEC_PER_SEC * drto_clks * drto_div, > + host->bus_hz); > > /* add a bit spare time */ > drto_ms += 10;