i2c: fix i2c transfer error when irqs disabled

diff --git a/drivers/i2c/busses/i2c-rockchip.c b/drivers/i2c/busses/i2c-rockchip.c
index 634ecc64db144685e948fd5f8534a53b715cf6a6..f1c5d9d2ef2b7770dfae68b367012831121e5155 100644 (file)
--- a/drivers/i2c/busses/i2c-rockchip.c
+++ b/drivers/i2c/busses/i2c-rockchip.c
@@ -77,14 +77,8 @@ struct rockchip_i2c {
        unsigned int            suspended:1;
 
        struct i2c_msg          *msg;
-       union {
-               unsigned int    msg_num;
-               unsigned int    is_busy;
-       };
-       union {
-               unsigned int    msg_idx;
-               int             error;
-       };
+       unsigned int            is_busy;
+       int                     error;
        unsigned int            msg_ptr;
 
        unsigned int            irq;
@@ -630,6 +624,8 @@ static int rockchip_i2c_doxfer(struct rockchip_i2c *i2c,
         * max cycles: (32 + 2 + 3) * 9 --> 400 cycles
         */
        int msleep_time = 400 * 1000 / i2c->scl_rate;   // ms
+       int can_sleep = !(in_atomic() || irqs_disabled());
+       int cpu = smp_processor_id();
 
        if (i2c->suspended) {
                dev_err(i2c->dev, "i2c is suspended\n");
@@ -659,22 +655,44 @@ static int rockchip_i2c_doxfer(struct rockchip_i2c *i2c,
        i2c->state = STATE_START;
        i2c->complete_what = 0;
        i2c_writel(I2C_STARTIEN, i2c->regs + I2C_IEN);
-       spin_unlock_irqrestore(&i2c->lock, flags);
 
        rockchip_i2c_enable(i2c, (i2c->count > 32) ? 0 : 1);    //if count > 32,  byte(32) send ack
 
-       if (in_atomic()) {
+       if (can_sleep) {
+               long ret = msecs_to_jiffies(I2C_WAIT_TIMEOUT);
+               if (i2c->is_busy) {
+                       DEFINE_WAIT(wait);
+                       for (;;) {
+                               prepare_to_wait(&i2c->wait, &wait, TASK_UNINTERRUPTIBLE);
+                               if (i2c->is_busy == 0)
+                                       break;
+                               spin_unlock_irqrestore(&i2c->lock, flags);
+                               ret = schedule_timeout(ret);
+                               spin_lock_irqsave(&i2c->lock, flags);
+                               if (!ret)
+                                       break;
+                       }
+                       if (!ret && (i2c->is_busy == 0))
+                               ret = 1;
+                       finish_wait(&i2c->wait, &wait);
+               }
+               timeout = ret;
+       } else {
                int tmo = I2C_WAIT_TIMEOUT * USEC_PER_MSEC;
-               while (tmo-- && i2c->is_busy != 0)
+               while (tmo-- && i2c->is_busy != 0) {
+                       spin_unlock_irqrestore(&i2c->lock, flags);
                        udelay(1);
+                       if (cpu == 0 && irqs_disabled()
+                           && (i2c_readl(i2c->regs + I2C_IPD)
+                               & i2c_readl(i2c->regs + I2C_IEN))) {
+                               rockchip_i2c_irq(i2c->irq, i2c);
+                       }
+                       spin_lock_irqsave(&i2c->lock, flags);
+               }
                timeout = (tmo <= 0) ? 0 : 1;
-       } else
-               timeout = wait_event_timeout(i2c->wait, (i2c->is_busy == 0), msecs_to_jiffies(I2C_WAIT_TIMEOUT));
+       }
 
-       spin_lock_irqsave(&i2c->lock, flags);
-       i2c->state = STATE_IDLE;
        error = i2c->error;
-       spin_unlock_irqrestore(&i2c->lock, flags);
 
        if (timeout == 0) {
                unsigned int ipd = i2c_readl(i2c->regs + I2C_IPD);
@@ -687,21 +705,19 @@ static int rockchip_i2c_doxfer(struct rockchip_i2c *i2c,
                                msgs[0].addr, i2c->state, i2c->is_busy, error, i2c->complete_what, ipd);
                        //rockchip_show_regs(i2c);
                        error = -ETIMEDOUT;
-                       if (in_atomic())
-                               mdelay(msleep_time);
-                       else
-                               msleep(msleep_time);
+                       mdelay(msleep_time);
                        rockchip_i2c_send_stop(i2c);
-                       if (in_atomic())
-                               mdelay(1);
-                       else
-                               msleep(1);
+                       mdelay(1);
                } else
                        i2c_dbg(i2c->dev, "Addr[0x%02x] wait event timeout, but transfer complete\n", i2c->addr);
        }
+
+       i2c->state = STATE_IDLE;
+
        i2c_writel(I2C_IPD_ALL_CLEAN, i2c->regs + I2C_IPD);
        rockchip_i2c_disable_irq(i2c);
        rockchip_i2c_disable(i2c);
+       spin_unlock_irqrestore(&i2c->lock, flags);
 
        if (error == -EAGAIN)
                i2c_dbg(i2c->dev, "No ack(complete_what: 0x%x), Maybe slave(addr: 0x%04x) not exist or abnormal power-on\n",
@@ -729,7 +745,7 @@ static int rockchip_i2c_xfer(struct i2c_adapter *adap,
                        state = rockchip_i2c_check_idle(i2c);
                        if (state == I2C_IDLE)
                                break;
-                       if (in_atomic())
+                       if (in_atomic() || irqs_disabled())
                                mdelay(10);
                        else
                                msleep(10);