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

[Andy Shevchenko]

On Mon, Feb 26, 2018 at 4:34 PM, Evgeniy Didin
<Evgeniy.Didin@xxxxxxxxxxxx> 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