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| author | Doug Anderson <dianders@chromium.org> | 2014-04-29 21:30:51 +0400 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2014-05-22 12:09:22 +0400 |
| commit | a83bea7c1170ad8c68d65ed2fff6a533e68f67a4 (patch) | |
| tree | 0bf15296942f62d84c0e67be5622b316eaa5e388 /Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt | |
| parent | 482116badacba9308abd6c5cae2f5f19e2f81449 (diff) | |
| download | linux-a83bea7c1170ad8c68d65ed2fff6a533e68f67a4.tar.xz | |
i2c: mux: Add more warnings to i2c-arb-gpio-challenge docs
This adds some more warnings to the i2c-arb-gpio-challenge docs to
help encourage people not to use it in their designs unless they have
no choice.
Signed-off-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt')
| -rw-r--r-- | Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt index 1ac8ea8ade1d..bfeabb843941 100644 --- a/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt +++ b/Documentation/devicetree/bindings/i2c/i2c-arb-gpio-challenge.txt @@ -8,6 +8,12 @@ the standard I2C multi-master rules. Using GPIOs is generally useful in the case where there is a device on the bus that has errata and/or bugs that makes standard multimaster mode not feasible. +Note that this scheme works well enough but has some downsides: +* It is nonstandard (not using standard I2C multimaster) +* Having two masters on a bus in general makes it relatively hard to debug + problems (hard to tell if i2c issues were caused by one master, another, or + some device on the bus). + Algorithm: |