diff mbox series

tools: termios_linux.h: Fix tcsendbreak() implementation

Message ID 20211006123025.9788-1-pali@kernel.org
State Accepted
Commit a46877eeb2de77d8d1daf1ea362423b6d2fc4f09
Delegated to: Stefan Roese
Headers show
Series tools: termios_linux.h: Fix tcsendbreak() implementation | expand

Commit Message

Pali Rohár Oct. 6, 2021, 12:30 p.m. UTC
There are two Linux ioctls which implements tcsendbreak() functionality:
TCSBRK and TCSBRKP

TCSBRK with non-zero parameter implements tcdrain() and with zero parameter
implements tcsendbreak() for duration of 0.25s.

TCSBRKP with zero parameter is same as TCSBRK and with non-zero parameter
implements tcsendbreak() for duration in deciseconds specified by
parameter. TCSBRKP does not have to be provided by older toolchain
versions.

So tcsendbreak() has to either use TCSBRK with zero parameter or TCSBRKP
with any parameter.

Fix code to use TCSBRKP and fallback to TCSBRK with 0.

Signed-off-by: Pali Rohár <pali@kernel.org>
---
 tools/termios_linux.h | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Stefan Roese Oct. 21, 2021, 5:36 a.m. UTC | #1
On 06.10.21 14:30, Pali Rohár wrote:
> There are two Linux ioctls which implements tcsendbreak() functionality:
> TCSBRK and TCSBRKP
> 
> TCSBRK with non-zero parameter implements tcdrain() and with zero parameter
> implements tcsendbreak() for duration of 0.25s.
> 
> TCSBRKP with zero parameter is same as TCSBRK and with non-zero parameter
> implements tcsendbreak() for duration in deciseconds specified by
> parameter. TCSBRKP does not have to be provided by older toolchain
> versions.
> 
> So tcsendbreak() has to either use TCSBRK with zero parameter or TCSBRKP
> with any parameter.
> 
> Fix code to use TCSBRKP and fallback to TCSBRK with 0.
> 
> Signed-off-by: Pali Rohár <pali@kernel.org>

Reviewed-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan

> ---
>   tools/termios_linux.h | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/tools/termios_linux.h b/tools/termios_linux.h
> index d73989b625a2..e100c8e4eb5f 100644
> --- a/tools/termios_linux.h
> +++ b/tools/termios_linux.h
> @@ -90,7 +90,11 @@ static inline int tcflush(int fd, int q)
>   
>   static inline int tcsendbreak(int fd, int d)
>   {
> -	return ioctl(fd, TCSBRK, d);
> +#ifdef TCSBRKP
> +	return ioctl(fd, TCSBRKP, d);
> +#else
> +	return ioctl(fd, TCSBRK, 0);
> +#endif
>   }
>   
>   static inline int tcflow(int fd, int a)
> 


Viele Grüße,
Stefan
Stefan Roese Oct. 21, 2021, 7:46 a.m. UTC | #2
On 21.10.21 07:36, Stefan Roese wrote:
> On 06.10.21 14:30, Pali Rohár wrote:
>> There are two Linux ioctls which implements tcsendbreak() functionality:
>> TCSBRK and TCSBRKP
>>
>> TCSBRK with non-zero parameter implements tcdrain() and with zero 
>> parameter
>> implements tcsendbreak() for duration of 0.25s.
>>
>> TCSBRKP with zero parameter is same as TCSBRK and with non-zero parameter
>> implements tcsendbreak() for duration in deciseconds specified by
>> parameter. TCSBRKP does not have to be provided by older toolchain
>> versions.
>>
>> So tcsendbreak() has to either use TCSBRK with zero parameter or TCSBRKP
>> with any parameter.
>>
>> Fix code to use TCSBRKP and fallback to TCSBRK with 0.
>>
>> Signed-off-by: Pali Rohár <pali@kernel.org>
> 
> Reviewed-by: Stefan Roese <sr@denx.de>

Applied to u-boot-marvell/master

Thanks,
Stefan

> Thanks,
> Stefan
> 
>> ---
>>   tools/termios_linux.h | 6 +++++-
>>   1 file changed, 5 insertions(+), 1 deletion(-)
>>
>> diff --git a/tools/termios_linux.h b/tools/termios_linux.h
>> index d73989b625a2..e100c8e4eb5f 100644
>> --- a/tools/termios_linux.h
>> +++ b/tools/termios_linux.h
>> @@ -90,7 +90,11 @@ static inline int tcflush(int fd, int q)
>>   static inline int tcsendbreak(int fd, int d)
>>   {
>> -    return ioctl(fd, TCSBRK, d);
>> +#ifdef TCSBRKP
>> +    return ioctl(fd, TCSBRKP, d);
>> +#else
>> +    return ioctl(fd, TCSBRK, 0);
>> +#endif
>>   }
>>   static inline int tcflow(int fd, int a)
>>
> 
> 
> Viele Grüße,
> Stefan
> 


Viele Grüße,
Stefan
diff mbox series

Patch

diff --git a/tools/termios_linux.h b/tools/termios_linux.h
index d73989b625a2..e100c8e4eb5f 100644
--- a/tools/termios_linux.h
+++ b/tools/termios_linux.h
@@ -90,7 +90,11 @@  static inline int tcflush(int fd, int q)
 
 static inline int tcsendbreak(int fd, int d)
 {
-	return ioctl(fd, TCSBRK, d);
+#ifdef TCSBRKP
+	return ioctl(fd, TCSBRKP, d);
+#else
+	return ioctl(fd, TCSBRK, 0);
+#endif
 }
 
 static inline int tcflow(int fd, int a)