I2C: Fix OMAP I2C status register handling in IRQ processing

The IRQ handler in omap-i2c.c can sometimes clear status bits without
actually processing them.  In particular, error status bits will be
ignored if any of the ARDY, RRDY, RDR, XRDY, or XDR bits are
concurrently set.

Signed-off-by: Seth Forshee <seth.forshee@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 4777466437e15397a771fbe56dd9e3bf38abc379..a16d513d85493498585643e05d32ccae0e4ba67d 100644 (file)
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -590,7 +590,7 @@ omap_i2c_isr(int this_irq, void *dev_id)
        struct omap_i2c_dev *dev = dev_id;
        u16 bits;
        u16 stat, w;
-       int count = 0;
+       int err, count = 0;
 
        if (dev->idle)
                return IRQ_NONE;
@@ -605,10 +605,19 @@ omap_i2c_isr(int this_irq, void *dev_id)
 
                omap_i2c_write_reg(dev, OMAP_I2C_STAT_REG, stat);
 
-               if (stat & OMAP_I2C_STAT_ARDY) {
-                       omap_i2c_complete_cmd(dev, 0);
-                       continue;
+               err = 0;
+               if (stat & OMAP_I2C_STAT_NACK) {
+                       err |= OMAP_I2C_STAT_NACK;
+                       omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
+                                          OMAP_I2C_CON_STP);
                }
+               if (stat & OMAP_I2C_STAT_AL) {
+                       dev_err(dev->dev, "Arbitration lost\n");
+                       err |= OMAP_I2C_STAT_AL;
+               }
+               if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
+                                       OMAP_I2C_STAT_AL))
+                       omap_i2c_complete_cmd(dev, err);
                if (stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR)) {
                        u8 num_bytes = 1;
                        if (dev->fifo_size) {
@@ -640,7 +649,6 @@ omap_i2c_isr(int this_irq, void *dev_id)
                                }
                        }
                        omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_RRDY | OMAP_I2C_STAT_RDR));
-                       continue;
                }
                if (stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR)) {
                        u8 num_bytes = 1;
@@ -674,7 +682,6 @@ omap_i2c_isr(int this_irq, void *dev_id)
                                omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
                        }
                        omap_i2c_ack_stat(dev, stat & (OMAP_I2C_STAT_XRDY | OMAP_I2C_STAT_XDR));
-                       continue;
                }
                if (stat & OMAP_I2C_STAT_ROVR) {
                        dev_err(dev->dev, "Receive overrun\n");
@@ -684,15 +691,6 @@ omap_i2c_isr(int this_irq, void *dev_id)
                        dev_err(dev->dev, "Transmit overflow\n");
                        dev->cmd_err |= OMAP_I2C_STAT_XUDF;
                }
-               if (stat & OMAP_I2C_STAT_NACK) {
-                       omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_NACK);
-                       omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
-                                          OMAP_I2C_CON_STP);
-               }
-               if (stat & OMAP_I2C_STAT_AL) {
-                       dev_err(dev->dev, "Arbitration lost\n");
-                       omap_i2c_complete_cmd(dev, OMAP_I2C_STAT_AL);
-               }
        }
 
        return count ? IRQ_HANDLED : IRQ_NONE;