diff options
| author | Daniel Kurtz <djkurtz@chromium.org> | 2012-07-24 16:13:58 +0400 |
|---|---|---|
| committer | Jean Delvare <khali@endymion.delvare> | 2012-07-24 16:13:58 +0400 |
| commit | 70a1cc1952355404a5746c88757f5a444df52b04 (patch) | |
| tree | b97d76988c4ac5781faf3edd8bde4021eadc1ad1 | |
| parent | 0ba8b8bfd56533f0b9af7513c6ebbc10c79ae052 (diff) | |
| download | linux-70a1cc1952355404a5746c88757f5a444df52b04.tar.xz | |
i2c-i801: Check and return errors during byte-by-byte transfers
If an error is detected in the polling loop, abort the transaction and
return an error code.
* DEV_ERR is set if the device does not respond with an acknowledge, and
the SMBus controller times out (minimum 25ms).
* BUS_ERR is set if a bus arbitration collision is detected. In other
words, when the SMBus controller tries to generate a START condition, but
detects that the SMBDATA is being held low, usually by another SMBus/I2C
master.
* FAILED is only set if a transaction is stopped by software (using
the SMBHSTCNT KILL bit).
Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
| -rw-r--r-- | drivers/i2c/busses/i2c-i801.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c index 05f394938b82..40a50f780972 100644 --- a/drivers/i2c/busses/i2c-i801.c +++ b/drivers/i2c/busses/i2c-i801.c @@ -131,9 +131,11 @@ #define SMBHSTSTS_INTR 0x02 #define SMBHSTSTS_HOST_BUSY 0x01 -#define STATUS_FLAGS (SMBHSTSTS_BYTE_DONE | SMBHSTSTS_FAILED | \ - SMBHSTSTS_BUS_ERR | SMBHSTSTS_DEV_ERR | \ - SMBHSTSTS_INTR) +#define STATUS_ERROR_FLAGS (SMBHSTSTS_FAILED | SMBHSTSTS_BUS_ERR | \ + SMBHSTSTS_DEV_ERR) + +#define STATUS_FLAGS (SMBHSTSTS_BYTE_DONE | SMBHSTSTS_INTR | \ + STATUS_ERROR_FLAGS) /* Older devices have their ID defined in <linux/pci_ids.h> */ #define PCI_DEVICE_ID_INTEL_COUGARPOINT_SMBUS 0x1c22 @@ -384,7 +386,7 @@ static int i801_block_transaction_byte_by_byte(struct i801_priv *priv, do { usleep_range(250, 500); status = inb_p(SMBHSTSTS(priv)); - } while ((!(status & SMBHSTSTS_BYTE_DONE)) + } while (!(status & (SMBHSTSTS_BYTE_DONE | STATUS_ERROR_FLAGS)) && (timeout++ < MAX_RETRIES)); result = i801_check_post(priv, status, timeout > MAX_RETRIES); |