From: Russell King rmk+kernel@armlinux.org.uk
[ Upstream commit e81c979f4e071d516aa27cf5a0c3939da00dc1ca ]
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 rmk+kernel@armlinux.org.uk Signed-off-by: Wolfram Sang wsa@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/i2c/busses/i2c-pxa.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c index 2c3c3d6935c0f..c9cbc9894bacf 100644 --- a/drivers/i2c/busses/i2c-pxa.c +++ b/drivers/i2c/busses/i2c-pxa.c @@ -706,11 +706,9 @@ static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c) { 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)); }