On Mon, Nov 9, 2015 at 10:25 PM, Andy Shevchenko
<andy.shevchenko@xxxxxxxxx> wrote:
> On Mon, Nov 9, 2015 at 7:43 AM, Liguo Zhang <liguo.zhang@xxxxxxxxxxxx> wrote:
>> For platform with auto restart support, between every transfer,
>> i2c controller will trigger an interrupt and SW need to handle
>> it to start new transfer. When doing write-then-read transfer,
>> instead of restart mechanism, using WRRD mode to have controller
>> send both transfer in one request to reduce latency.
>
>
>> @@ -518,6 +529,16 @@ static int mtk_i2c_transfer(struct i2c_adapter *adap,
>> if (ret)
>> return ret;
>>
>> + i2c->auto_restart = i2c->dev_comp->auto_restart;
>> +
>> + /* checking if we can skip restart and optimize using WRRD mode */
>> + if (i2c->auto_restart && num == 2) {
>> + if (!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD) &&
>> + msgs[0].addr == msgs[1].addr) {
>
> Nitpick (optional):
>
> ((msgs[0].flags & msgs[1].flags) & I2C_M_RD)
> ?
IMHO, this makes the code less readable.
Leave this to the compiler's optimizer.
-Dan
>
>> + i2c->auto_restart = 0;
>> + }
>> + }
>
> --
> With Best Regards,
> Andy Shevchenko
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
