Re: [PATCH 4/8 v3] i2c: i801: check and return errors duringbyte-by-byte transfers

From: Daniel Kurtz
Date: Wed Jun 27 2012 - 23:46:49 EST


On Thu, Jun 28, 2012 at 12:51 AM, Jean Delvare <khali@xxxxxxxxxxxx> wrote:
> On Wed, 27 Jun 2012 21:54:11 +0800, Daniel Kurtz wrote:
>> 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 the transaction is set by software (using the
>> SMBHSTCNT KILL bit).

That was supposed to say:

* FAILED is only set if a transaction is stopped by software (using
the SMBHSTCNT KILL bit).

> Not quite sure what you mean with "set by software". Other than this,
> patch looks good, applied, thanks.

Applied where?
I'd like to send a rebased patchset onto whatever you have already staged.

>
>>
>> Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
>> ---
>>  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 6a53338..ba56b74 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
>> @@ -385,7 +387,7 @@ 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);
>
>
> --
> Jean Delvare
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