Hi Stefan, On ven., 2016-06-24 at 13:57 +0200, Stefan Roese wrote: > Hi, > > I'm currently trying to use the SMBus on a congatec BayTrail board. > This works just fine when booting via the original BIOS. But when I > boot into Linux using U-Boot as bootloader, I get the following > errors: > > [ 81.877121] i801_smbus 0000:00:1f.3: Transaction timeout > [ 81.879228] i801_smbus 0000:00:1f.3: Failed terminating the transaction > [ 81.879320] i801_smbus 0000:00:1f.3: SMBus is busy, can't use it! > [ 81.879373] i801_smbus 0000:00:1f.3: SMBus is busy, can't use it! > [ 81.879421] i801_smbus 0000:00:1f.3: SMBus is busy, can't use it! > [ 81.879496] i801_smbus 0000:00:1f.3: SMBus is busy, can't use it! > ... > > I checked with an oscilloscope and the SMBus clock is not toggling > at all in this case. My feeling is, that some basic setup is missing > in this non-BIOS case. Like some clock enabling. Does anyone of you > have some idea here? No immediate idea, sorry. Two ideas: * Is this problem specific to Baytrail systems, or does i2c-i801 fail on all U-Boot systems? * Did you try comparing the PCI configuration space of the SMBus device between original BIOS boot (working) and U-Boot boot (not working)? -- 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
