Re: [PATCH] i2c: designware: Get right data length

乱石
2021-02-25T14:08:31Z

Hi,
在 2021/2/25 19:19, Andy Shevchenko 写道:
> On Thu, Feb 25, 2021 at 10:35:28AM +0800, Liguang Zhang wrote:
>> IC_DATA_CMD[11] indicates the first data byte received after the address
>> phase for receive transfer in Master receiver or Slave receiver mode,
>> this bit was set in some transfer flow. IC_DATA_CMD[7:0] contains the
>> data to be transmitted or received on the I2C bus, so we should use the
>> lower 8 bits to get the right data length.
> Thanks for the report and fix!
> My comments below.

Thanks for your comments. I will optimize my code follow your comments
and send v2 revision.

Regards,

Liguang

>
>> Signed-off-by: Liguang Zhang <zhangliguang@linux.alibaba.com>
>> ---
>> drivers/i2c/busses/i2c-designware-master.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c
>> index d6425ad6e6a3..c3cf76f6c607 100644
>> --- a/drivers/i2c/busses/i2c-designware-master.c
>> +++ b/drivers/i2c/busses/i2c-designware-master.c
>> @@ -432,7 +432,7 @@ i2c_dw_read(struct dw_i2c_dev *dev)
>> regmap_read(dev->map, DW_IC_DATA_CMD, &tmp);
>> /* Ensure length byte is a valid value */
>> if (flags & I2C_M_RECV_LEN &&
>> - tmp <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
>> + (tmp & 0xff) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
> Can we rather describe this as
>
> #define DW_IC_DATA_CMD_DAT GENMASK(7, 0)
>
> in *.h file and...
>
> (tmp & DW_IC_DATA_CMD_DAT) <= I2C_SMBUS_BLOCK_MAX && tmp > 0) {
> ...here?
>
>> len = i2c_dw_recv_len(dev, tmp);
>> }
>> *buf++ = tmp;
>> --
>> 2.19.1.6.gb485710b
>>