Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     gregkh@linuxfoundation.org
Cc:     johan@kernel.org, linux-usb@vger.kernel.org,
        linux-kernel@vger.kernel.org, Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: Re: Re: [PATCH v3] USB: serial: ftdi_sio: Convert to use dev_groups
Date:   Fri,  2 Sep 2022 22:33:46 +0800
Message-Id: <20220902143346.4120012-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

On Fri, Sep 02, 2022 at 05:56:13PM +0800, Greg KH wrote:
>>  drivers/usb/serial/ftdi_sio.c | 101 +++++++++++++++++-----------------
>>  1 file changed, 51 insertions(+), 50 deletions(-)
>> 
>> diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
>> index d5a3986dfee7..479c3a5caaf8 100644
>> --- a/drivers/usb/serial/ftdi_sio.c
>> +++ b/drivers/usb/serial/ftdi_sio.c
>> @@ -1107,11 +1107,40 @@ static u32 ftdi_232bm_baud_base_to_divisor(int baud, int base);
>>  static u32 ftdi_232bm_baud_to_divisor(int baud);
>>  static u32 ftdi_2232h_baud_base_to_divisor(int baud, int base);
>>  static u32 ftdi_2232h_baud_to_divisor(int baud);
>> +static umode_t ftdi_sio_attr_is_visible(struct kobject *kobj,
>> +					 struct attribute *attr, int idx);
>> +static ssize_t latency_timer_store(struct device *dev,
>> +				   struct device_attribute *attr,
>> +				   const char *valbuf, size_t count);
>> +static ssize_t event_char_store(struct device *dev,
>> +	struct device_attribute *attr, const char *valbuf, size_t count);
>> +static ssize_t latency_timer_show(struct device *dev,
>> +				  struct device_attribute *attr, char *buf);
>> +
> 
> Please work with the code so that you do not have to pre-define these
> functions.  It should be possible.  Worst case, you pre-define the
> structure for the driver, that should be it.

Without pre-definition of the functions, compilation errors will occur,
such as 'ftdi_sio_attr_is_visible' undeclared here.
I have no idea why they are not necessary.
Please explain in detail.

> And again, have you tested this change?

Every time I change the code, I recomplie it and check whether there are
errors.
Are there any other tests I need to do?

Thanks,
Jiang