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-rw-r--r--drivers/i2c/busses/Kconfig17
1 files changed, 10 insertions, 7 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index b4aaa1bd672..da77c37caf1 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -290,18 +290,21 @@ comment "I2C system bus drivers (mostly embedded / system-on-chip)"
config I2C_AT91
tristate "Atmel AT91 I2C Two-Wire interface (TWI)"
- depends on ARCH_AT91 && EXPERIMENTAL && BROKEN
+ depends on ARCH_AT91 && EXPERIMENTAL
help
This supports the use of the I2C interface on Atmel AT91
processors.
- This driver is BROKEN because the controller which it uses
- will easily trigger RX overrun and TX underrun errors. Using
- low I2C clock rates may partially work around those issues
- on some systems. Another serious problem is that there is no
- documented way to issue repeated START conditions, as needed
+ A serious problem is that there is no documented way to issue
+ repeated START conditions for more than two messages, as needed
to support combined I2C messages. Use the i2c-gpio driver
- unless your system can cope with those limitations.
+ unless your system can cope with this limitation.
+
+ Caution! at91rm9200, at91sam9261, at91sam9260, at91sam9263 devices
+ don't have clock stretching in transmission mode. For that reason,
+ you can encounter underrun issues causing premature stop sendings if
+ the latency to fill the transmission register is too long. If you
+ are facing this situation, use the i2c-gpio driver.
config I2C_AU1550
tristate "Au1550/Au1200/Au1300 SMBus interface"