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i2c-amd8111: Add proper error handling
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The functions the functions amd_ec_wait_write and amd_ec_wait_read have an
unsigned return type, but return a negative constant to indicate an error
condition.

A sematic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@exists@
identifier f;
constant C;
@@

 unsigned f(...)
 { <+...
*  return -C;
 ...+> }
// </smpl>

Fixing amd_ec_wait_write and amd_ec_wait_read leads to the need to adjust
the return type of the functions amd_ec_write and amd_ec_read, which are
the only functions that call amd_ec_wait_write and amd_ec_wait_read.
amd_ec_write and amd_ec_read, in turn, are only called from within the
function amd8111_access, which already returns a signed typed value.  Each
of the calls to amd_ec_write and amd_ec_read are updated using the
following semantic patch:

// <smpl>
@@
@@

+ status = amd_ec_write
- amd_ec_write
  (...);
+ if (status) return status;

@@
@@

+ status = amd_ec_read
- amd_ec_read
  (...);
+ if (status) return status;
// </smpl>

The patch also adds the declaration of the status variable.

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
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Julia Lawall authored and Jean Delvare committed Oct 24, 2010
1 parent ef9d9b8 commit 9cb2c27
Showing 1 changed file with 113 additions and 50 deletions.
163 changes: 113 additions & 50 deletions drivers/i2c/busses/i2c-amd8111.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -69,7 +69,7 @@ static struct pci_driver amd8111_driver;
* ACPI 2.0 chapter 13 access of registers of the EC
*/

static unsigned int amd_ec_wait_write(struct amd_smbus *smbus)
static int amd_ec_wait_write(struct amd_smbus *smbus)
{
int timeout = 500;

Expand All @@ -85,7 +85,7 @@ static unsigned int amd_ec_wait_write(struct amd_smbus *smbus)
return 0;
}

static unsigned int amd_ec_wait_read(struct amd_smbus *smbus)
static int amd_ec_wait_read(struct amd_smbus *smbus)
{
int timeout = 500;

Expand All @@ -101,7 +101,7 @@ static unsigned int amd_ec_wait_read(struct amd_smbus *smbus)
return 0;
}

static unsigned int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
static int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
unsigned char *data)
{
int status;
Expand All @@ -124,7 +124,7 @@ static unsigned int amd_ec_read(struct amd_smbus *smbus, unsigned char address,
return 0;
}

static unsigned int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
static int amd_ec_write(struct amd_smbus *smbus, unsigned char address,
unsigned char data)
{
int status;
Expand Down Expand Up @@ -196,7 +196,7 @@ static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
{
struct amd_smbus *smbus = adap->algo_data;
unsigned char protocol, len, pec, temp[2];
int i;
int i, status;

protocol = (read_write == I2C_SMBUS_READ) ? AMD_SMB_PRTCL_READ
: AMD_SMB_PRTCL_WRITE;
Expand All @@ -209,70 +209,117 @@ static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
break;

case I2C_SMBUS_BYTE:
if (read_write == I2C_SMBUS_WRITE)
amd_ec_write(smbus, AMD_SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE) {
status = amd_ec_write(smbus, AMD_SMB_CMD,
command);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_BYTE;
break;

case I2C_SMBUS_BYTE_DATA:
amd_ec_write(smbus, AMD_SMB_CMD, command);
if (read_write == I2C_SMBUS_WRITE)
amd_ec_write(smbus, AMD_SMB_DATA, data->byte);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE) {
status = amd_ec_write(smbus, AMD_SMB_DATA,
data->byte);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_BYTE_DATA;
break;

case I2C_SMBUS_WORD_DATA:
amd_ec_write(smbus, AMD_SMB_CMD, command);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE) {
amd_ec_write(smbus, AMD_SMB_DATA,
data->word & 0xff);
amd_ec_write(smbus, AMD_SMB_DATA + 1,
data->word >> 8);
status = amd_ec_write(smbus, AMD_SMB_DATA,
data->word & 0xff);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
data->word >> 8);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_WORD_DATA | pec;
break;

case I2C_SMBUS_BLOCK_DATA:
amd_ec_write(smbus, AMD_SMB_CMD, command);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE) {
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX);
amd_ec_write(smbus, AMD_SMB_BCNT, len);
for (i = 0; i < len; i++)
amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
if (status)
return status;
for (i = 0; i < len; i++) {
status =
amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
if (status)
return status;
}
}
protocol |= AMD_SMB_PRTCL_BLOCK_DATA | pec;
break;

case I2C_SMBUS_I2C_BLOCK_DATA:
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX);
amd_ec_write(smbus, AMD_SMB_CMD, command);
amd_ec_write(smbus, AMD_SMB_BCNT, len);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
if (status)
return status;
if (read_write == I2C_SMBUS_WRITE)
for (i = 0; i < len; i++)
amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
for (i = 0; i < len; i++) {
status =
amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
if (status)
return status;
}
protocol |= AMD_SMB_PRTCL_I2C_BLOCK_DATA;
break;

case I2C_SMBUS_PROC_CALL:
amd_ec_write(smbus, AMD_SMB_CMD, command);
amd_ec_write(smbus, AMD_SMB_DATA, data->word & 0xff);
amd_ec_write(smbus, AMD_SMB_DATA + 1, data->word >> 8);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_DATA,
data->word & 0xff);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_DATA + 1,
data->word >> 8);
if (status)
return status;
protocol = AMD_SMB_PRTCL_PROC_CALL | pec;
read_write = I2C_SMBUS_READ;
break;

case I2C_SMBUS_BLOCK_PROC_CALL:
len = min_t(u8, data->block[0],
I2C_SMBUS_BLOCK_MAX - 1);
amd_ec_write(smbus, AMD_SMB_CMD, command);
amd_ec_write(smbus, AMD_SMB_BCNT, len);
for (i = 0; i < len; i++)
amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
status = amd_ec_write(smbus, AMD_SMB_CMD, command);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_BCNT, len);
if (status)
return status;
for (i = 0; i < len; i++) {
status = amd_ec_write(smbus, AMD_SMB_DATA + i,
data->block[i + 1]);
if (status)
return status;
}
protocol = AMD_SMB_PRTCL_BLOCK_PROC_CALL | pec;
read_write = I2C_SMBUS_READ;
break;
Expand All @@ -282,24 +329,29 @@ static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
return -EOPNOTSUPP;
}

amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
status = amd_ec_write(smbus, AMD_SMB_ADDR, addr << 1);
if (status)
return status;
status = amd_ec_write(smbus, AMD_SMB_PRTCL, protocol);
if (status)
return status;

/* FIXME this discards status from ec_read(); so temp[0] will
* hold stack garbage ... the rest of this routine will act
* nonsensically. Ignored ec_write() status might explain
* some such failures...
*/
amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
if (status)
return status;

if (~temp[0] & AMD_SMB_STS_DONE) {
udelay(500);
amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
if (status)
return status;
}

if (~temp[0] & AMD_SMB_STS_DONE) {
msleep(1);
amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
status = amd_ec_read(smbus, AMD_SMB_STS, temp + 0);
if (status)
return status;
}

if ((~temp[0] & AMD_SMB_STS_DONE) || (temp[0] & AMD_SMB_STS_STATUS))
Expand All @@ -311,24 +363,35 @@ static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
switch (size) {
case I2C_SMBUS_BYTE:
case I2C_SMBUS_BYTE_DATA:
amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
status = amd_ec_read(smbus, AMD_SMB_DATA, &data->byte);
if (status)
return status;
break;

case I2C_SMBUS_WORD_DATA:
case I2C_SMBUS_PROC_CALL:
amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
status = amd_ec_read(smbus, AMD_SMB_DATA, temp + 0);
if (status)
return status;
status = amd_ec_read(smbus, AMD_SMB_DATA + 1, temp + 1);
if (status)
return status;
data->word = (temp[1] << 8) | temp[0];
break;

case I2C_SMBUS_BLOCK_DATA:
case I2C_SMBUS_BLOCK_PROC_CALL:
amd_ec_read(smbus, AMD_SMB_BCNT, &len);
status = amd_ec_read(smbus, AMD_SMB_BCNT, &len);
if (status)
return status;
len = min_t(u8, len, I2C_SMBUS_BLOCK_MAX);
case I2C_SMBUS_I2C_BLOCK_DATA:
for (i = 0; i < len; i++)
amd_ec_read(smbus, AMD_SMB_DATA + i,
data->block + i + 1);
for (i = 0; i < len; i++) {
status = amd_ec_read(smbus, AMD_SMB_DATA + i,
data->block + i + 1);
if (status)
return status;
}
data->block[0] = len;
break;
}
Expand Down

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