Re: [PATCH v3 0/4] P2040/P2041 i2c recovery erratum

[Joakim Tjernlund]

On Wed, 2021-05-12 at 09:20 +1200, Chris Packham wrote:
> The P2040/P2041 has an erratum where the i2c recovery scheme
> documented in the reference manual (and currently implemented
> in the i2c-mpc.c driver) does not work. The errata document
> provides an alternative that does work. This series implements
> that alternative and uses a property in the devicetree to
> decide when the alternative mechanism is needed.
> 
> Chris Packham (4):
>   dt-bindings: i2c: mpc: Add fsl,i2c-erratum-a004447 flag
>   powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P2041 i2c
>     controllers
>   powerpc/fsl: set fsl,i2c-erratum-a004447 flag for P1010 i2c
>     controllers
>   i2c: mpc: implement erratum A-004447 workaround
> 
>  .../devicetree/bindings/i2c/i2c-mpc.yaml      |  7 ++
>  arch/powerpc/boot/dts/fsl/p1010si-post.dtsi   |  8 ++
>  arch/powerpc/boot/dts/fsl/p2041si-post.dtsi   | 16 ++++
>  drivers/i2c/busses/i2c-mpc.c                  | 81 ++++++++++++++++++-
>  4 files changed, 110 insertions(+), 2 deletions(-)
> 

This now reminds me about the current I2C reset procedure, it didn't work for us and I came up with this one:
  https://www.spinics.net/lists/linux-i2c/msg29490.html
it never got in but we are still using it.

  Jocke