According to the "VFxxx Controller Reference Manual" (and the comment
block starting at line 97), Vybrid requires writing a one for clearing
an interrupt flag. Syncing the method for clearing I2SR_IIF in
i2c_imx_isr().

Signed-off-by: Christian Eggers <cegg...@arri.de>
Cc: sta...@vger.kernel.org
---
 drivers/i2c/busses/i2c-imx.c | 20 +++++++++++++++-----
 1 file changed, 15 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
index 0ab5381aa012..745f4071155a 100644
--- a/drivers/i2c/busses/i2c-imx.c
+++ b/drivers/i2c/busses/i2c-imx.c
@@ -412,6 +412,19 @@ static void i2c_imx_dma_free(struct imx_i2c_struct 
*i2c_imx)
        dma->chan_using = NULL;
 }
 
+static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int 
bits)
+{
+       unsigned int temp;
+
+       /*
+        * i2sr_clr_opcode is the value to clear all interrupts.
+        * Here we want to clear only <bits>, so we write
+        * ~i2sr_clr_opcode with just <bits> toggled.
+        */
+       temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits;
+       imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+}
+
 static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool 
atomic)
 {
        unsigned long orig_jiffies = jiffies;
@@ -424,8 +437,7 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, 
int for_busy, bool a
 
                /* check for arbitration lost */
                if (temp & I2SR_IAL) {
-                       temp &= ~I2SR_IAL;
-                       imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+                       i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
                        return -EAGAIN;
                }
 
@@ -623,9 +635,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
        if (temp & I2SR_IIF) {
                /* save status register */
                i2c_imx->i2csr = temp;
-               temp &= ~I2SR_IIF;
-               temp |= (i2c_imx->hwdata->i2sr_clr_opcode & I2SR_IIF);
-               imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
+               i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
                wake_up(&i2c_imx->queue);
                return IRQ_HANDLED;
        }
-- 
Christian Eggers
Embedded software developer

Arnold & Richter Cine Technik GmbH & Co. Betriebs KG
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: 
HRA 57918
Persoenlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH
Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: 
HRB 54477
Geschaeftsfuehrer: Dr. Michael Neuhaeuser; Stephan Schenk; Walter Trauninger; 
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