target/linux/generic/backport-5.4/819-v5.8-i2c-pxa-clear-all-master-action-bits-in-i2c_pxa_stop.patch

   1 From: Russell King <rmk+kernel@armlinux.org.uk>
   2 Bcc: linux@mail.armlinux.org.uk
   3 Subject: [PATCH 5/7] i2c: pxa: clear all master action bits in
   4  i2c_pxa_stop_message()
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   9
  10 If we timeout during a message transfer, the control register may
  11 contain bits that cause an action to be set. Read-modify-writing the
  12 register leaving these bits set may trigger the hardware to attempt
  13 one of these actions unintentionally.
  14
  15 Always clear these bits when cleaning up after a message or after
  16 a timeout.
  17
  18 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  19 ---
  20  drivers/i2c/busses/i2c-pxa.c | 6 ++----
  21  1 file changed, 2 insertions(+), 4 deletions(-)
  22
  23 diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
  24 index db739cce93ac..a72d07bdb793 100644
  25 --- a/drivers/i2c/busses/i2c-pxa.c
  26 +++ b/drivers/i2c/busses/i2c-pxa.c
  27 @@ -795,11 +795,9 @@ static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
  28  {
  29         u32 icr;
  30
  31 -       /*
  32 -        * Clear the STOP and ACK flags
  33 -        */
  34 +       /* Clear the START, STOP, ACK, TB and MA flags */
  35         icr = readl(_ICR(i2c));
  36 -       icr &= ~(ICR_STOP | ICR_ACKNAK);
  37 +       icr &= ~(ICR_START | ICR_STOP | ICR_ACKNAK | ICR_TB | ICR_MA);
  38         writel(icr, _ICR(i2c));
  39  }
  40
  41 --
  42 2.20.1
  43