On Tuesday 04 August 2015 09:02:39 Peter Ujfalusi wrote: > On 08/03/2015 09:48 PM, Jarkko Nikula wrote: > > It is well possible that some regression got introduced to > > TPA6130A2 I2C communication over the years without nobody than you > > now notices. We used to do QA back in Meego N900 days but that was > > pre 3.x kernels. > > No major changes has been done to the tpa driver during the past > years... I wanted to do some updates, like moving it to regmap, but > as you said, n900 is the only user (and n9) and I do not feel > comfortable to hack on a device where I do not have serial > console... And I'm using the n900 time to time also. > > >> So maybe something similar? Kernel expects that some PM or > >> regulator parts are initialized, but they are only sometimes? > >> Just speculation... > > > > I'm thinking the same. I could figure SCL could be stuck low if TPA > > or some other chip connected to the same I2C bus is without power > > and is pulling I2C signals down. > > What would happen with the SCL stuck on i2c.2 bus if you remove the > tpa driver from the kernel? If you remove the other drivers for the > devices on i2c.2? Hi Peter and Jarkko! Do you have some code samples for testing? Or something else which I can test? This problem is still reproducible on more N900 devices and I would like to see it fixed. -- Pali Rohár pali.rohar@xxxxxxxxx
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