target/linux/generic/backport-5.4/814-v5.8-i2c-pxa-fix-i2c_pxa_wait_bus_not_busy-boundary-condi.patch

   1 From: Russell King <rmk+kernel@armlinux.org.uk>
   2 Bcc: linux@mail.armlinux.org.uk
   3 Cc: linux-i2c@vger.kernel.org
   4 Subject: [PATCH 12/17] i2c: pxa: fix i2c_pxa_wait_bus_not_busy() boundary
   5  condition
   6 MIME-Version: 1.0
   7 Content-Disposition: inline
   8 Content-Transfer-Encoding: 8bit
   9 Content-Type: text/plain; charset="utf-8"
  10
  11 Fix i2c_pxa_wait_bus_not_busy()'s boundary conditions, so that a
  12 coincidental success and timeout results in the function returning
  13 success.
  14
  15 Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
  16 ---
  17  drivers/i2c/busses/i2c-pxa.c | 17 ++++++++++++-----
  18  1 file changed, 12 insertions(+), 5 deletions(-)
  19
  20 --- a/drivers/i2c/busses/i2c-pxa.c
  21 +++ b/drivers/i2c/busses/i2c-pxa.c
  22 @@ -417,19 +417,26 @@ static void i2c_pxa_abort(struct pxa_i2c
  23  static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
  24  {
  25         int timeout = DEF_TIMEOUT;
  26 +       u32 isr;
  27
  28 -       while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
  29 -               if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
  30 +       while (1) {
  31 +               isr = readl(_ISR(i2c));
  32 +               if (!(isr & (ISR_IBB | ISR_UB)))
  33 +                       return 0;
  34 +
  35 +               if (isr & ISR_SAD)
  36                         timeout += 4;
  37
  38 +               if (!timeout--)
  39 +                       break;
  40 +
  41                 msleep(2);
  42                 show_state(i2c);
  43         }
  44
  45 -       if (timeout < 0)
  46 -               show_state(i2c);
  47 +       show_state(i2c);
  48
  49 -       return timeout < 0 ? I2C_RETRY : 0;
  50 +       return I2C_RETRY;
  51  }
  52
  53  static int i2c_pxa_wait_master(struct pxa_i2c *i2c)