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 diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
  21 index b2c7765756e2..19505ffbb8f1 100644
  22 --- a/drivers/i2c/busses/i2c-pxa.c
  23 +++ b/drivers/i2c/busses/i2c-pxa.c
  24 @@ -417,19 +417,26 @@ static void i2c_pxa_abort(struct pxa_i2c *i2c)
  25  static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
  26  {
  27         int timeout = DEF_TIMEOUT;
  28 +       u32 isr;
  29
  30 -       while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
  31 -               if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
  32 +       while (1) {
  33 +               isr = readl(_ISR(i2c));
  34 +               if (!(isr & (ISR_IBB | ISR_UB)))
  35 +                       return 0;
  36 +
  37 +               if (isr & ISR_SAD)
  38                         timeout += 4;
  39
  40 +               if (!timeout--)
  41 +                       break;
  42 +
  43                 msleep(2);
  44                 show_state(i2c);
  45         }
  46
  47 -       if (timeout < 0)
  48 -               show_state(i2c);
  49 +       show_state(i2c);
  50
  51 -       return timeout < 0 ? I2C_RETRY : 0;
  52 +       return I2C_RETRY;
  53  }
  54
  55  static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
  56 --
  57 2.20.1
  58