diff mbox series

[4.19,018/206] i2c: pxa: clear all master action bits in i2c_pxa_stop_message()

Message ID 20200623195317.861496954@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg Kroah-Hartman June 23, 2020, 7:55 p.m. UTC 
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 mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index fbf91d383b409..7248ba6763e45 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));
 }