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