Hello Marek,
On Tue, Aug 14, 2012 at 2:50 PM, Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
> Dear Tomas Hlavacek,
>
>> +static ssize_t get_attr_uartclk(struct device *dev,
>> + struct device_attribute *attr, char *buf)
>> +{
>> + int ret;
>> +
>> + struct uart_state *state = (struct uart_state *)(dev_get_drvdata(dev));
>
> You don't need this cast here.
Yes, you are right. Thanks.
>
>> + mutex_lock(&state->port.mutex);
>> + ret = snprintf(buf, PAGE_SIZE, "%d\n", state->uart_port->uartclk);
>
> Do you really need such a large buffer (PAGE_SIZE) ?
Well no, but I believe that I get the buffer of length equal to
PAGE_SIZE anyway. Documentation/filesystems/sysfs.txt says so on line
179.
>
>> + mutex_unlock(&state->port.mutex);
>> + return ret;
>> +}
>> +
>> +static ssize_t set_attr_uartclk(struct device *dev,
>> + struct device_attribute *attr, const char *buf, size_t count)
>> +{
>> + struct uart_state *state = (struct uart_state *)(dev_get_drvdata(dev));
>> + unsigned int val;
>> + int ret;
>> +
>> + ret = kstrtouint(buf, 10, &val);
>> + if (ret)
>> + return ret;
>> +
>> + mutex_lock(&state->port.mutex);
>> +
>> + /*
>> + * Check value: baud_base has to be more than 9600
>> + * and uartclock = baud_base * 16 .
>> + */
>> + if (val >= 153600)
>> + state->uart_port->uartclk = val;
>
> This magic value here would use some documentation.
OK. Do you think this would be sufficient comment?:
/*
* Check value: baud_base does not make sense to be set below 9600
* and since uartclock = (baud_base * 16) it has to be equal or greater than
* 9600 * 16 = 153600.
*/
PATCHv2 follows.
Tomas
--
Tomáš Hlaváček <tmshlvck@xxxxxxxxx>
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