Messages in this thread | | | Date | Tue, 27 Feb 2018 11:02:45 +0800 | From | Jisheng Zhang <> | Subject | Re: [PATCH 0/2 v3] mmc: dw_mmc: Fix DTO/STO timeout overflow calculation |
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On Mon, 26 Feb 2018 17:34:11 +0300 Evgeniy Didin wrote:
> For some 32-bit architectures calculation of DTO and STO timeout can be incorrect > due to multiply overflow. Lets prevent this by casting multiply and result to u64. > > Suggested by Jisheng Zhang. > Switch DIV_ROUND_UP macro to DIV_ROUND_UP_ULL is not reasonable > because overflow happens on multiply and DIV_ROUND_UP_ULL helps > with sum overflow.
hmmm, I mean something as below:
-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);
This could avoid build error in arm case.
> > --- > Changes since v2: > -add fix for cto_ms > > Evgeniy Didin (2): > mmc: dw_mmc: Fix the DTO timeout overflow calculation for 32-bit > systems > mmc: dw_mmc: Fix the CTO overflow calculation for 32-bit systems
These two patches could be folded into one patch?
Thanks
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