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i2c: buses: add i2c bus driver for NVIDIA GPU

PATCH Superseded Wolfram Sang 1 participant 1 message Oct 1, 2018 USB

v12 of 15 Superseded Latest is v15 →

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PATCH v12 1/2 i2c: buses: add i2c bus driver for NVIDIA GPU

Quoted 15 lines · Ajay Gupta

Hi Heikki and Peter,

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Can we get the working set in while the issues is being debugged?

I'm not the one making the decision, and I don't even know if this is going through the i2c or the usb tree? If it's going through the i2c tree you need a tag from the usb people (Greg?) on patch 2/2, and if it's going through the usb tree, you need a tag from Wolfram on patch 1/2. As I said, I'm not involved with that part, I'm just reviewing these patches because I felt like it.

The remaining issue that bothers me is the looping reads, and your email address reveals that you should be in a very good position to work out why they do not work, and fix it or let us know why they don't.

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I am working with different teams to debug this and I think it may take some time to know the root cause.

We got confirmation from HW team about 4 byte read limitation. There has to be a STOP after every single read cycle. One read cycle supports maximum of 4 byte burst. I will update the patches with a comment on this.

Could it be that this is more an SMBus controller than an I2C controller? I haven't looked at the specs but maybe populating smbus_xfer instead of master_xfer is an option here?