[coreboot-gerrit] Change in coreboot[master]: device/dram: Add method for converting MHz to MT/s

[Rob Barnes (Code Review)]

Rob Barnes has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/45343 )

Change subject: device/dram: Add method for converting MHz to MT/s
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Patch Set 1:

(1 comment)

https://review.coreboot.org/c/coreboot/+/45343/1/src/device/dram/ddr4.c 
File src/device/dram/ddr4.c:

https://review.coreboot.org/c/coreboot/+/45343/1/src/device/dram/ddr4.c@24 
PS1, Line 24: 800,
> I understand what's being done here, but it just seems odd that 801MHz would be classified as DDR4_1 […]

According to the standard, DDR4-1866 tck can range from 1.071ns to <1.25ns, or 934 MHz to >800Mhz. So, yes 801 MHz is within DDR4-1866 range. Whether this should be reported as 1866 MT/s or 1602 MT/s is another question. For SMBIOS, we decided to report 1866 MT/s because this is more common and the difference is unlikely to be meaningful.