From 24d0fb423ca18adf509dec8a7326c0bdd6653e41 Mon Sep 17 00:00:00 2001 From: David Brownell Date: Sat, 13 Oct 2007 23:56:32 +0200 Subject: [PATCH] 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 Signed-off-by: Jean Delvare --- drivers/i2c/busses/Kconfig | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index a9cab3e5b8bd..de95c75efb41 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -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 -- 2.20.1