From: Russell King Bcc: linux@mail.armlinux.org.uk Subject: [PATCH 5/7] i2c: pxa: clear all master action bits in i2c_pxa_stop_message() MIME-Version: 1.0 Content-Disposition: inline Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="utf-8" If we timeout during a message transfer, the control register may contain bits that cause an action to be set. Read-modify-writing the register leaving these bits set may trigger the hardware to attempt one of these actions unintentionally. Always clear these bits when cleaning up after a message or after a timeout. Signed-off-by: Russell King --- drivers/i2c/busses/i2c-pxa.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) --- a/drivers/i2c/busses/i2c-pxa.c +++ b/drivers/i2c/busses/i2c-pxa.c @@ -754,11 +754,9 @@ static inline void i2c_pxa_stop_message( { u32 icr; - /* - * Clear the STOP and ACK flags - */ + /* Clear the START, STOP, ACK, TB and MA flags */ icr = readl(_ICR(i2c)); - icr &= ~(ICR_STOP | ICR_ACKNAK); + icr &= ~(ICR_START | ICR_STOP | ICR_ACKNAK | ICR_TB | ICR_MA); writel(icr, _ICR(i2c)); }