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SubjectRe: [PATCH 2/2 v3] mmc: dw_mmc: Fix the CTO overflow calculation for 32-bit systems
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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