Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.14 017/136] i2c: pxa: clear all master action bits in i2c_pxa_stop_message() | Date | Tue, 23 Jun 2020 21:57:53 +0200 |
| |
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 600d264e080c5..ecc84aea51319 100644 --- a/drivers/i2c/busses/i2c-pxa.c +++ b/drivers/i2c/busses/i2c-pxa.c @@ -709,11 +709,9 @@ 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)); } -- 2.25.1
| |