Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux

Pull i2c bugfixes from Wolfram Sang:
 "I2C driver bugfixes for the 3.17 release.  Details can be found in the
  commit messages, yet I think this is typical driver stuff"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Revert "i2c: rcar: remove spinlock"
  i2c: at91: add bound checking on SMBus block length bytes
  i2c: rk3x: fix bug that cause transfer fails in master receive mode
  i2c: at91: Fix a race condition during signal handling in at91_do_twi_xfer.
  i2c: mv64xxx: continue probe when clock-frequency is missing
  i2c: rcar: fix MNR interrupt handling

4 files changed, 62 insertions, 14 deletions

diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 79a68999a696..917d54588d95 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -101,6 +101,7 @@ struct at91_twi_dev {
         unsigned twi_cwgr_reg;
         struct at91_twi_pdata *pdata;
         bool use_dma;
+        bool recv_len_abort;
         struct at91_twi_dma dma;
 };
 
@@ -267,12 +268,24 @@ static void at91_twi_read_next_byte(struct at91_twi_dev *dev)
         *dev->buf = at91_twi_read(dev, AT91_TWI_RHR) & 0xff;
         --dev->buf_len;
 
+        /* return if aborting, we only needed to read RHR to clear RXRDY*/
+        if (dev->recv_len_abort)
+                return;
+
         /* handle I2C_SMBUS_BLOCK_DATA */
         if (unlikely(dev->msg->flags & I2C_M_RECV_LEN)) {
-                dev->msg->flags &= ~I2C_M_RECV_LEN;
-                dev->buf_len += *dev->buf;
-                dev->msg->len = dev->buf_len + 1;
-                dev_dbg(dev->dev, "received block length %d\n", dev->buf_len);
+                /* ensure length byte is a valid value */
+                if (*dev->buf <= I2C_SMBUS_BLOCK_MAX && *dev->buf > 0) {
+                        dev->msg->flags &= ~I2C_M_RECV_LEN;
+                        dev->buf_len += *dev->buf;
+                        dev->msg->len = dev->buf_len + 1;
+                        dev_dbg(dev->dev, "received block length %d\n",
+                                         dev->buf_len);
+                } else {
+                        /* abort and send the stop by reading one more byte */
+                        dev->recv_len_abort = true;
+                        dev->buf_len = 1;
+                }
         }
 
         /* send stop if second but last byte has been read */
@@ -421,8 +434,8 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
                 }
         }
 
-        ret = wait_for_completion_interruptible_timeout(&dev->cmd_complete,
-                                                        dev->adapter.timeout);
+        ret = wait_for_completion_io_timeout(&dev->cmd_complete,
+                                             dev->adapter.timeout);
         if (ret == 0) {
                 dev_err(dev->dev, "controller timed out\n");
                 at91_init_twi_bus(dev);
@@ -444,6 +457,12 @@ static int at91_do_twi_transfer(struct at91_twi_dev *dev)
                 ret = -EIO;
                 goto error;
         }
+        if (dev->recv_len_abort) {
+                dev_err(dev->dev, "invalid smbus block length recvd\n");
+                ret = -EPROTO;
+                goto error;
+        }
+
         dev_dbg(dev->dev, "transfer complete\n");
 
         return 0;
@@ -500,6 +519,7 @@ static int at91_twi_xfer(struct i2c_adapter *adap, struct i2c_msg *msg, int num)
         dev->buf_len = m_start->len;
         dev->buf = m_start->buf;
         dev->msg = m_start;
+        dev->recv_len_abort = false;
 
         ret = at91_do_twi_transfer(dev);
 
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 6dc5ded86f62..2f64273d3f2b 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -746,8 +746,7 @@ mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
         }
         tclk = clk_get_rate(drv_data->clk);
 
-        rc = of_property_read_u32(np, "clock-frequency", &bus_freq);
-        if (rc)
+        if (of_property_read_u32(np, "clock-frequency", &bus_freq))
                 bus_freq = 100000; /* 100kHz by default */
 
         if (!mv64xxx_find_baud_factors(bus_freq, tclk,
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index f3c7139dfa25..1cc146cfc1f3 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -34,6 +34,7 @@
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/slab.h>
+#include <linux/spinlock.h>
 
 /* register offsets */
 #define ICSCR   0x00    /* slave ctrl */
@@ -95,6 +96,7 @@ struct rcar_i2c_priv {
         struct i2c_msg  *msg;
         struct clk *clk;
 
+        spinlock_t lock;
         wait_queue_head_t wait;
 
         int pos;
@@ -365,20 +367,20 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
         struct rcar_i2c_priv *priv = ptr;
         u32 msr;
 
+        /*-------------- spin lock -----------------*/
+        spin_lock(&priv->lock);
+
         msr = rcar_i2c_read(priv, ICMSR);
 
+        /* Only handle interrupts that are currently enabled */
+        msr &= rcar_i2c_read(priv, ICMIER);
+
         /* Arbitration lost */
         if (msr & MAL) {
                 rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST));
                 goto out;
         }
 
-        /* Stop */
-        if (msr & MST) {
-                rcar_i2c_flags_set(priv, ID_DONE);
-                goto out;
-        }
-
         /* Nack */
         if (msr & MNR) {
                 /* go to stop phase */
@@ -388,6 +390,12 @@ static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
                 goto out;
         }
 
+        /* Stop */
+        if (msr & MST) {
+                rcar_i2c_flags_set(priv, ID_DONE);
+                goto out;
+        }
+
         if (rcar_i2c_is_recv(priv))
                 rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr));
         else
@@ -400,6 +408,9 @@ out:
                 wake_up(&priv->wait);
         }
 
+        spin_unlock(&priv->lock);
+        /*-------------- spin unlock -----------------*/
+
         return IRQ_HANDLED;
 }
 
@@ -409,14 +420,21 @@ static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
 {
         struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
         struct device *dev = rcar_i2c_priv_to_dev(priv);