Hi Hrvoje, On Sat, 4 Feb 2017 02:55:02 +0100, Hrvoje T wrote: > My hardware is HP Probook 6470b laptop, kernel 4.8.0-37-generic, > lm-sensors version 1:3.4.0-3. I did > > # modprobe i2c-dev > # i2cdetect -l > > and got this: > > i2c-3 i2c i915 gmbus dpc I2C adapter > i2c-1 i2c i915 gmbus vga I2C adapter > i2c-8 i2c DPDDC-D I2C adapter > i2c-6 i2c DPDDC-B I2C adapter > i2c-4 i2c i915 gmbus dpb I2C adapter > i2c-2 i2c i915 gmbus panel I2C adapter > i2c-0 i2c i915 gmbus ssc I2C adapter > i2c-7 i2c DPDDC-C I2C adapter > i2c-5 i2c i915 gmbus dpd I2C adapter No SMBus here, all the I2C buses listed are from your graphics chip. > I would like to find out CAS latency times of my RAM memory modules > without opening the laptop. I guess those are on DIMM slots. dmidecode > -t memory gives: > > Handle 0x0008, DMI type 17, 34 bytes > Memory Device > Array Handle: 0x0005 > Error Information Handle: Not Provided > Total Width: 64 bits > Data Width: 64 bits > Size: 4096 MB > Form Factor: SODIMM > Set: None > Locator: Bottom-Slot 2(under) > Bank Locator: BANK 2 > Type: DDR3 > Type Detail: Synchronous > Speed: 1600 MHz > Manufacturer: Ramaxel > Serial Number: 44BBE80E > Asset Tag: 9876543210 > Part Number: RMT3160ED58E9W1600 > Rank: Unknown > Configured Clock Speed: Unknown Looks good, but DMI doesn't provide detailed timing information, only speed. > and lspci: > (...) > 00:1f.0 ISA bridge: Intel Corporation HM76 Express Chipset LPC > Controller (rev 04) > 00:1f.2 SATA controller: Intel Corporation 7 Series Chipset Family > 6-port SATA Controller [AHCI mode] (rev 04) The SMBus should show up as device 00:1f.3 here, but it is missing. It means it has been hidden by the BIOS. We have some quirks in the kernel to unhide the SMBus on older Intel chipsets, up to ICH6, but nothing for recent chipsets. > I know I could find out latency times on the manufacturer's web page, > but I would like to know is it possible via i2c? I'm noob in Linux and > bad at english, sorry for my mistakes and thanks for your help in > advance. It would be possible if the BIOS did not hide the SMBus device. But not on your laptop, at least not until someone adds another PCI quirk to unhide this specific device after reading its datasheet. You may try booting memtest86 on your laptop (many Linux distributions include it on their installation media), it may be able to display the timing information you are looking for. Alternatively, temporarily put the memory module in question in another laptop where the SMBus is not hidden, and capture a dump of the SPD data. -- Jean Delvare SUSE L3 Support -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
