From 9cb2c2726e9ae212ccaeecd3eaadcd8d49ac7400 Mon Sep 17 00:00:00 2001 From: Julia Lawall Date: Sun, 24 Oct 2010 18:16:58 +0200 Subject: [PATCH] i2c-amd8111: Add proper error handling 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/) // @exists@ identifier f; constant C; @@ unsigned f(...) { <+... * return -C; ...+> } // 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: // @@ @@ + status = amd_ec_write - amd_ec_write (...); + if (status) return status; @@ @@ + status = amd_ec_read - amd_ec_read (...); + if (status) return status; // The patch also adds the declaration of the status variable. Signed-off-by: Julia Lawall Signed-off-by: Jean Delvare --- drivers/i2c/busses/i2c-amd8111.c | 163 +++++++++++++++++++++---------- 1 file changed, 113 insertions(+), 50 deletions(-) diff --git a/drivers/i2c/busses/i2c-amd8111.c b/drivers/i2c/busses/i2c-amd8111.c index af1e5e254b7b..6b6a6b1d7025 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, - 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; @@ -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, - 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; @@ -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)) @@ -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; }