1 files changed, 17 insertions, 10 deletions

diff --git a/drivers/i2c/busses/scx200_acb.c b/drivers/i2c/busses/scx200_acb.c
index 22a3eda04166..eae9e81be375 100644
--- a/drivers/i2c/busses/scx200_acb.c
+++ b/drivers/i2c/busses/scx200_acb.c
@@ -184,21 +184,21 @@ static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
                 break;
 
         case state_read:
-                /* Set ACK if receiving the last byte */
-                if (iface->len == 1)
+                /* Set ACK if _next_ byte will be the last one */
+                if (iface->len == 2)
                         outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
                 else
                         outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
 
-                *iface->ptr++ = inb(ACBSDA);
-                --iface->len;
-
-                if (iface->len == 0) {
+                if (iface->len == 1) {
                         iface->result = 0;
                         iface->state = state_idle;
                         outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
                 }
 
+                *iface->ptr++ = inb(ACBSDA);
+                --iface->len;
+
                 break;
 
         case state_write:
@@ -232,7 +232,7 @@ static void scx200_acb_poll(struct scx200_acb_iface *iface)
         unsigned long timeout;
 
         timeout = jiffies + POLL_TIMEOUT;
-        while (time_before(jiffies, timeout)) {
+        while (1) {
                 status = inb(ACBST);
 
                 /* Reset the status register to avoid the hang */
@@ -242,7 +242,10 @@ static void scx200_acb_poll(struct scx200_acb_iface *iface)
                         scx200_acb_machine(iface, status);
                         return;
                 }
-                yield();
+                if (time_after(jiffies, timeout))
+                        break;
+                cpu_relax();
+                cond_resched();
         }
 
         dev_err(&iface->adapter.dev, "timeout in state %s\n",
@@ -307,8 +310,12 @@ static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
                 buffer = (u8 *)&cur_word;
                 break;
 
-        case I2C_SMBUS_BLOCK_DATA:
+        case I2C_SMBUS_I2C_BLOCK_DATA:
+                if (rw == I2C_SMBUS_READ)
+                        data->block[0] = I2C_SMBUS_BLOCK_MAX; /* For now */
                 len = data->block[0];
+                if (len == 0 || len > I2C_SMBUS_BLOCK_MAX)
+                        return -EINVAL;
                 buffer = &data->block[1];
                 break;
 
@@ -372,7 +379,7 @@ static u32 scx200_acb_func(struct i2c_adapter *adapter)
 {
         return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
                I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
-               I2C_FUNC_SMBUS_BLOCK_DATA;
+               I2C_FUNC_SMBUS_I2C_BLOCK;
 }
 
 /* For now, we only handle combined mode (smbus) */