* [PATCH] USB: serial: Correct return value on read
@ 2017-11-26 16:18 Gimcuan Hui
2017-11-27 10:21 ` Johan Hovold
0 siblings, 1 reply; 3+ messages in thread
From: Gimcuan Hui @ 2017-11-26 16:18 UTC (permalink / raw)
To: Johan Hovold; +Cc: gregkh, linux-usb, linux-kernel
It's meaningless to return buf[0] on read. Because the caller of this
interface checks the return value negative or not. Instead, we should
return the result variable.
Signed-off-by: Gimcuan Hui <gimcuan@gmail.com>
---
drivers/usb/serial/ark3116.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
index 3c544782f60b..bfdbc7164e7b 100644
--- a/drivers/usb/serial/ark3116.c
+++ b/drivers/usb/serial/ark3116.c
@@ -101,11 +101,9 @@ static int ark3116_read_reg(struct usb_serial *serial,
reg, result);
if (result >= 0)
result = -EIO;
-
- return result;
}
- return buf[0];
+ return result;
}
static inline int calc_divisor(int bps)
--
2.11.0
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] USB: serial: Correct return value on read
2017-11-26 16:18 [PATCH] USB: serial: Correct return value on read Gimcuan Hui
@ 2017-11-27 10:21 ` Johan Hovold
2017-11-27 14:21 ` saks cuso
0 siblings, 1 reply; 3+ messages in thread
From: Johan Hovold @ 2017-11-27 10:21 UTC (permalink / raw)
To: Gimcuan Hui; +Cc: Johan Hovold, gregkh, linux-usb, linux-kernel
On Sun, Nov 26, 2017 at 04:18:51PM +0000, Gimcuan Hui wrote:
> It's meaningless to return buf[0] on read. Because the caller of this
> interface checks the return value negative or not. Instead, we should
> return the result variable.
It's not really meaningless, it's just that the return value is no
longer being used the way it was originally intended. I think
"redundant" and/or "confusing" would be a more appropriate description.
> Signed-off-by: Gimcuan Hui <gimcuan@gmail.com>
> ---
> drivers/usb/serial/ark3116.c | 4 +---
> 1 file changed, 1 insertion(+), 3 deletions(-)
>
> diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
> index 3c544782f60b..bfdbc7164e7b 100644
> --- a/drivers/usb/serial/ark3116.c
> +++ b/drivers/usb/serial/ark3116.c
> @@ -101,11 +101,9 @@ static int ark3116_read_reg(struct usb_serial *serial,
> reg, result);
> if (result >= 0)
> result = -EIO;
> -
> - return result;
> }
>
> - return buf[0];
> + return result;
Also we do not want to return the value of result on success as that
would always be 1 (i.e. the buffer size).
You could change this function, and also the write_reg one, to return 0
on success since this is a more common pattern.
Please also rephrase your commit summary (Subject) since you're not
really "correcting" (as in fixing) anything here. This is more a of nice
clean up, even if it could potentially also prevent future bugs.
Thanks,
Johan
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] USB: serial: Correct return value on read
2017-11-27 10:21 ` Johan Hovold
@ 2017-11-27 14:21 ` saks cuso
0 siblings, 0 replies; 3+ messages in thread
From: saks cuso @ 2017-11-27 14:21 UTC (permalink / raw)
To: Johan Hovold; +Cc: Greg Kroah-Hartman, linux-usb, linux-kernel
On 27 November 2017 at 10:21, Johan Hovold <johan@kernel.org> wrote:
> On Sun, Nov 26, 2017 at 04:18:51PM +0000, Gimcuan Hui wrote:
>> It's meaningless to return buf[0] on read. Because the caller of this
>> interface checks the return value negative or not. Instead, we should
>> return the result variable.
>
> It's not really meaningless, it's just that the return value is no
> longer being used the way it was originally intended. I think
> "redundant" and/or "confusing" would be a more appropriate description.
>
yes, i will use "confusing" instead.
>> Signed-off-by: Gimcuan Hui <gimcuan@gmail.com>
>> ---
>> drivers/usb/serial/ark3116.c | 4 +---
>> 1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/drivers/usb/serial/ark3116.c b/drivers/usb/serial/ark3116.c
>> index 3c544782f60b..bfdbc7164e7b 100644
>> --- a/drivers/usb/serial/ark3116.c
>> +++ b/drivers/usb/serial/ark3116.c
>> @@ -101,11 +101,9 @@ static int ark3116_read_reg(struct usb_serial *serial,
>> reg, result);
>> if (result >= 0)
>> result = -EIO;
>> -
>> - return result;
>> }
>>
>> - return buf[0];
>> + return result;
>
> Also we do not want to return the value of result on success as that
> would always be 1 (i.e. the buffer size).
>
> You could change this function, and also the write_reg one, to return 0
> on success since this is a more common pattern.
>
> Please also rephrase your commit summary (Subject) since you're not
> really "correcting" (as in fixing) anything here. This is more a of nice
> clean up, even if it could potentially also prevent future bugs.
>
> Thanks,
> Johan
agree, v2 will be post soon.
thank you for correcting.
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2017-11-27 14:21 UTC | newest]
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2017-11-26 16:18 [PATCH] USB: serial: Correct return value on read Gimcuan Hui
2017-11-27 10:21 ` Johan Hovold
2017-11-27 14:21 ` saks cuso
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