Hello Wolfram,
Thank you for your feedback!
-----Original Message----- From: Wolfram Sang [mailto:wsa@the-dreams.de] Sent: 29 May 2018 18:20 To: Fabrizio Castro fabrizio.castro@bp.renesas.com Cc: Greg Kroah-Hartman gregkh@linuxfoundation.org; linux-i2c@vger.kernel.org; Chris Paterson Chris.Paterson2@renesas.com; Biju Das biju.das@bp.renesas.com; stable@vger.kernel.org; Ben Hutchings ben.hutchings@codethink.co.uk Subject: Re: [PATCH 0/6] Fix R-Car I2C data byte sent twice issue
this series fixes an issue with the I2C driver of the Renesas R-Car and RZ/G1 family of chips. The issue is clearly visible with the CIP kernel (4.4) running on a iwg20d board from iWave due to the way the bq32000 driver/device is interacting with the I2C driver/controller. In the stable kernel (4.4) there is no support for the iwg20d, I tried to replicate the same problem on a Koelsch board with no success, but the problem is there.
For the record, this patchset was developed on a Lager board (R-Car H2) but the issue was known to be present on other Gen2 SoCs, too. This was a nasty race condition. IIRC I was able to reproduce the issue only with the first transfer after boot (for whatever reason). And fixing it, together with another issue (double address byte), needed all this refactoring.
Thank you for the information, I may give it a try.
I might try to recap how this double data byte problem was triggered. This is somewhere on my todo-list anyhow. Just to check if the same problem is still present with Gen3 SoCs. No promises, but I'll see what I can do.
Thanks, Fab
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