On Mon, Apr 15, 2019 at 2:24 PM Jean Delvare <jdelvare@xxxxxxx> wrote:
>
> On Mon, 15 Apr 2019 14:47:12 +0300, Jarkko Nikula wrote:
> > On 4/12/19 9:42 PM, Jean Delvare wrote:
> > > Jarkko, are you aware of any setting of the Z370 SMBus controller that
> > > would block writes to I2C address 0x36? I have a vague memory of some
> > > setting that aimed at protecting SPD EEPROMs but as I remember it was
> > > only for address range 0x50-0x57. But I don't remember the details to
> > > be honest.
> >
> > Not sure but specification for SMBus Host Configuration register (0x40)
> > bit SPD Write Disable (SPDWD) says only 0x50-0x57:
> >
> > "When this bit is set to 1, writes to SMBus addresses 50h – 57h are
> > disabled. Note: This bit is R/WO and will be reset on PLTRST# assertion.
> > This bit should be set by BIOS to ‘1’. Software can only program this
> > bit when both the START bit and Host Busy bit are ‘0’; otherwise, the
> > write may result in undefined behavior."
>
> Thanks Jarkko, that's what I found as well when looking specifically in
> the datasheet of the Z370 chipset.
>
> From the dump provided by Dreamcat4:
>
> > 40: 11 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>
> The SPD protection is indeed enabled, as I would expect. But it should
> not affect SPD page selection which is in address range 0x30-0x37.
>
> Anyway it's not possible to disable the SPD protection at run-time, as
> the bit is Write-Once according to the spreadsheet.
>
> I'm out of idea, sorry. The only thing I can suggest is to try
> different memory modules on this mainboard, and/or these memory modules
> on another mainboard, to figure out if the problem comes from the
> memory modules or the mainboard.
Jean, I have just tried different ram kit in same motherboard. And it
does not seem to be doing much differently, its same behaviour, same
error messages.
[root:~] # ./decode-dimms.new
Cannot read /sys/bus/i2c/drivers/ee1004/2-0050/eeprom at
./decode-dimms.new line 2358.
dmesg -w
[ 763.518594] ee1004 2-0050: Failed to select page 0 (-6)
decode-dimms (older version with ubuntu distribution):
[root:/] # decode-dimms
No EEPROM found, try loading the eeprom or at24 module
[root:/] # decode-dimms
No EEPROM found, try loading the eeprom or at24 module
[root:/] # decode-dimms
No EEPROM found, try loading the eeprom or at24 module
[root:/] # decode-dimms
No EEPROM found, try loading the eeprom or at24 module
[root:/] #
other command:
[root:/] # modprobe i2c-dev
[root:/] # i2cdetect 2
Error: Could not open file `/dev/i2c-2' or `/dev/i2c/2': No such file
or directory
[root:/] 1 # cd /sys/bus/i2c/devices/
[root:/sys/bus/i2c/devices] # ls
i2c-0 i2c-1
[root:/sys/bus/i2c/devices] # sudo modprobe i2c-i801
[root:/sys/bus/i2c/devices] # ls
i2c-0 i2c-1 i2c-2
[root:/sys/bus/i2c/devices] # modprobe ee1004
[root:/sys/bus/i2c/devices] #
[root:/sys/bus/i2c/devices] #
[root:/sys/bus/i2c/devices] # i2cdetect 2
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-2.
I will probe address range 0x03-0x77.
Continue? [Y/n] y
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- 08 -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- 18 -- 1a -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: 30 31 -- -- 34 35 -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- 44 -- -- -- -- -- -- -- -- -- -- --
50: 50 -- 52 -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
[root:/sys/bus/i2c/devices] #
[root:/sys/bus/i2c/devices] # modprobe ee1004
[root:/sys/bus/i2c/devices] #
dmesg -w
[ 271.121124] i801_smbus 0000:00:1f.4: SPD Write Disable is set
[ 271.121155] i801_smbus 0000:00:1f.4: SMBus using PCI interrupt
[ 413.409031] ee1004 2-0050: 512 byte EE1004-compliant SPD EEPROM, read-only
[ 413.409044] i2c i2c-2: new_device: Instantiated device ee1004 at 0x50
[ 425.137122] ee1004 2-0052: 512 byte EE1004-compliant SPD EEPROM, read-only
[ 425.137139] i2c i2c-2: new_device: Instantiated device ee1004 at 0x52
[ 620.196055] ee1004 2-0050: Currently selected page: 1
[ 620.196056] ee1004 2-0050: 512 byte EE1004-compliant SPD EEPROM, read-only
[ 620.196275] ee1004 2-0052: Currently selected page: 1
[ 620.196276] ee1004 2-0052: 512 byte EE1004-compliant SPD EEPROM, read-only
>
> You could also try your memory modules separately, in case the problem
> is a bad interaction between the 2. The SPD page selection is kind of a
> broadcast command, affecting all memory modules at once, and I'm not
> really sure what would happen if one module behaves OK and the other
> not.
>
> --
> Jean Delvare
> SUSE L3 Support
