Re: [PATCH 7/8] drivers/i2c/busses/i2c-amd8111.c: Fix unsignedreturn type

From: Jean Delvare
Date: Fri Oct 01 2010 - 09:22:20 EST

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Hi Julia,

On Thu, 30 Sep 2010 22:27:02 +0200 (CEST), Julia Lawall wrote:
> 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@xxxxxxx>
>
> ---
> Only compile tested.

Can't test it either, no hardware.

>
> drivers/i2c/busses/i2c-amd8111.c | 152 ++++++++++++++------
> 1 files changed, 110 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-amd8111.c b/drivers/i2c/busses/i2c-amd8111.c
> index af1e5e2..e12c584 100644
> --- a/drivers/i2c/busses/i2c-amd8111.c
> +++ b/drivers/i2c/busses/i2c-amd8111.c
> @@ -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;
>
> @@ -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;
>
> @@ -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;
> @@ -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;
> @@ -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;
> @@ -209,38 +209,62 @@ 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,
> + status = amd_ec_write(smbus, AMD_SMB_DATA,
> data->word & 0xff);
> - amd_ec_write(smbus, AMD_SMB_DATA + 1,
> + 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;
> @@ -248,19 +272,35 @@ static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
> 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;
> @@ -268,11 +308,18 @@ static s32 amd8111_access(struct i2c_adapter * adap, u16 addr,
> 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,
> + 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;
> @@ -282,24 +329,34 @@ 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...
> */

This comment can go away now :)

> - 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))
> @@ -311,24 +368,35 @@ 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;
> }

Patch looks good, applied (for 2.6.37, as it doesn't fix any reported
issue), thanks.

--
Jean Delvare
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