i2c: Bus drivers return -Errno not -1

Tighten error paths used by various i2c adapters (mostly x86) so
they return real fault/errno codes instead of a "-1" (which is
most often interpreted as "-EPERM").  Build tested, with eyeball
review.

One minor initial goal is to have adapters consistently return
the code "-ENXIO" when addressing a device doesn't get an ACK
response, at least in the probe paths where they are already
good at stifling related logspam.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

1 files changed, 17 insertions, 6 deletions

diff --git a/drivers/i2c/busses/i2c-ali1563.c b/drivers/i2c/busses/i2c-ali1563.c
index 6b68074e518a..30bd3ee70386 100644
--- a/drivers/i2c/busses/i2c-ali1563.c
+++ b/drivers/i2c/busses/i2c-ali1563.c
@@ -67,6 +67,7 @@ static int ali1563_transaction(struct i2c_adapter * a, int size)
 {
         u32 data;
         int timeout;
+        int status = -EIO;
 
         dev_dbg(&a->dev, "Transaction (pre): STS=%02x, CNTL1=%02x, "
                 "CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
@@ -103,13 +104,15 @@ static int ali1563_transaction(struct i2c_adapter * a, int size)
                 /* Issue 'kill' to host controller */
                 outb_p(HST_CNTL2_KILL,SMB_HST_CNTL2);
                 data = inb_p(SMB_HST_STS);
+                status = -ETIMEDOUT;
         }
 
         /* device error - no response, ignore the autodetection case */
-        if ((data & HST_STS_DEVERR) && (size != HST_CNTL2_QUICK)) {
-                dev_err(&a->dev, "Device error!\n");
+        if (data & HST_STS_DEVERR) {
+                if (size != HST_CNTL2_QUICK)
+                        dev_err(&a->dev, "Device error!\n");
+                status = -ENXIO;
         }
-
         /* bus collision */
         if (data & HST_STS_BUSERR) {
                 dev_err(&a->dev, "Bus collision!\n");
@@ -122,13 +125,14 @@ static int ali1563_transaction(struct i2c_adapter * a, int size)
                 outb_p(0x0,SMB_HST_CNTL2);
         }
 
-        return -1;
+        return status;
 }
 
 static int ali1563_block_start(struct i2c_adapter * a)
 {
         u32 data;
         int timeout;
+        int status = -EIO;
 
         dev_dbg(&a->dev, "Block (pre): STS=%02x, CNTL1=%02x, "
                 "CNTL2=%02x, CMD=%02x, ADD=%02x, DAT0=%02x, DAT1=%02x\n",
@@ -164,13 +168,20 @@ static int ali1563_block_start(struct i2c_adapter * a)
 
         if (timeout && !(data & HST_STS_BAD))
                 return 0;
+
+        if (timeout == 0)
+                status = -ETIMEDOUT;
+
+        if (data & HST_STS_DEVERR)
+                status = -ENXIO;
+
         dev_err(&a->dev, "SMBus Error: %s%s%s%s%s\n",
-                timeout ? "Timeout " : "",
+                timeout ? "" : "Timeout ",
                 data & HST_STS_FAIL ? "Transaction Failed " : "",
                 data & HST_STS_BUSERR ? "No response or Bus Collision " : "",
                 data & HST_STS_DEVERR ? "Device Error " : "",
                 !(data & HST_STS_DONE) ? "Transaction Never Finished " : "");
-        return -1;
+        return status;
 }
 
 static int ali1563_block(struct i2c_adapter * a, union i2c_smbus_data * data, u8 rw)