i2c-at91: Mark as broken

Mark the i2c-at91 driver BROKEN in Kconfig, and explain just
why it's broken.  (Summary:  hardware design issues.)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
This commit is contained in:
David Brownell 2007-10-13 23:56:32 +02:00 committed by Jean Delvare
parent 08fb68bb4b
commit 24d0fb423c

View File

@ -75,11 +75,19 @@ config I2C_AMD8111
config I2C_AT91
tristate "Atmel AT91 I2C Two-Wire interface (TWI)"
depends on ARCH_AT91 && EXPERIMENTAL
depends on ARCH_AT91 && EXPERIMENTAL && BROKEN
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
to support combined I2C messages. Use the i2c-gpio driver
unless your system can cope with those limitations.
config I2C_AU1550
tristate "Au1550/Au1200 SMBus interface"
depends on SOC_AU1550 || SOC_AU1200