Comment 15 for bug 1019863

Hi,

I have not commented on this bug for some time, but I will like to provide the final analysis so that it can be closed up for good.
After not seeing any crashes/freezes when I used Toshiba 256 MB SDRAM modules (Toshiba module with Toshiba DRAM devices), I tried playing around with different combinations of the original 2 (two) 128 MB SDRAM modules and 1 (one) 256 MB SDRAM module.
It turns out one of the no brand 128 MB SDRAM module with Mosel Vitelic DRAM devices seems to cause crashes/freezes when I put the computer into ACPI S3 State and wake it up.
It appears that the self refresh mode of this 128 MB SDRAM module with Mosel Vitelic DRAM device causes memory content corruption, and this leads Ubuntu to freeze/crash at some point (i.e., After putting the computer in and out of ACPI S3 State so many times.).
Just for the record, the marking of the DRAM device says V54C3128804VAT7 with a date code 0213 (13th week of 2002).
I assume I just got a bad memory module.
    I didn't notice this until now, and insisted that memtest86+ didn't catch any memory read/write error, but if I think about it, memtest86+ is powerless as a tool against this type of a failure is because it doesn't have the means to put the memory into self refresh mode and bring it out to check the content of the memory array.
While this case is specific to SDRAM, this type of failure can occur on any DRAM type since SDRAM because all of them now have self refresh mode.
So if there is anyone reading this analysis, remember that the memory array can get corrupted if for some reason self refresh mode no longer works correctly (i.e., due to aging), and this can lead to seemingly random crashes/freezes after waking the computer up from ACPI S3 State.
I know that this case is already closed and I am now happy to finally close this case as well.

Regards,

fpgahardwareengineer