Messages in this thread | | | From | Andy Shevchenko <> | Date | Mon, 26 Feb 2018 16:39:55 +0200 | Subject | Re: [PATCH 2/2 v3] mmc: dw_mmc: Fix the CTO overflow calculation for 32-bit systems |
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On Mon, Feb 26, 2018 at 4:34 PM, Evgeniy Didin <Evgeniy.Didin@synopsys.com> wrote: > In commit 4c2357f57dd5 ("mmc: dw_mmc: Fix the CTO timeout calculation") > have been made changes which can cause multiply overflow for 32-bit systems. > The value of cto_ms is lower the drto_ms, but nevertheless overflow can occur. > Lets cast this multiply to u64 type which prevents overflow.
> - cto_ms = DIV_ROUND_UP(MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz); > + > + cto_ms = DIV_ROUND_UP((u64)MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz);
IIRC, someone commented on this or similar, i.e.
DIV_ROUND_UP_ULL() ?
-- With Best Regards, Andy Shevchenko
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