[PATCH] tty: serial: Fix bit order in RS485 flag definitions

[PATCH] tty: serial: Fix bit order in RS485 flag definitions

[Christoph Niedermaier]

Since the commit 93f3350c46fa ("RS485: fix inconsistencies in the
meaning of some variables"), the definition for bit 3 has been removed.
But with the switch to bit shift marcos in commit 76ac8e29855b ("tty:
serial: Cleanup the bit shift with macro"), this gap wasn't preserved.
To avoid a break in user/kernel api of the system skip bit 3 again and
add a placeholder comment.

Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
---
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
Cc: Jiri Slaby <jirislaby@kernel.org>
Cc: Lukas Wunner <lukas@wunner.de>
Cc: Lino Sanfilippo <l.sanfilippo@kunbus.com>
To: linux-serial@vger.kernel.org
To: linux-arm-kernel@lists.infradead.org
---
 include/uapi/linux/serial.h | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h
index 9086367db043..de9b4733607e 100644
--- a/include/uapi/linux/serial.h
+++ b/include/uapi/linux/serial.h
@@ -145,12 +145,13 @@ struct serial_rs485 {
 #define SER_RS485_ENABLED		_BITUL(0)
 #define SER_RS485_RTS_ON_SEND		_BITUL(1)
 #define SER_RS485_RTS_AFTER_SEND	_BITUL(2)
-#define SER_RS485_RX_DURING_TX		_BITUL(3)
-#define SER_RS485_TERMINATE_BUS		_BITUL(4)
-#define SER_RS485_ADDRB			_BITUL(5)
-#define SER_RS485_ADDR_RECV		_BITUL(6)
-#define SER_RS485_ADDR_DEST		_BITUL(7)
-#define SER_RS485_MODE_RS422		_BITUL(8)
+/* Placeholder for bit 3: SER_RS485_RTS_BEFORE_SEND, which isn't used anymore */
+#define SER_RS485_RX_DURING_TX		_BITUL(4)
+#define SER_RS485_TERMINATE_BUS		_BITUL(5)
+#define SER_RS485_ADDRB			_BITUL(6)
+#define SER_RS485_ADDR_RECV		_BITUL(7)
+#define SER_RS485_ADDR_DEST		_BITUL(8)
+#define SER_RS485_MODE_RS422		_BITUL(9)
 
 	__u32	delay_rts_before_send;
 	__u32	delay_rts_after_send;
-- 
2.11.0

Re: [PATCH] tty: serial: Fix bit order in RS485 flag definitions

[Greg Kroah-Hartman]

On Thu, Jan 18, 2024 at 01:43:50PM +0100, Christoph Niedermaier wrote:
> Since the commit 93f3350c46fa ("RS485: fix inconsistencies in the
> meaning of some variables"), the definition for bit 3 has been removed.
> But with the switch to bit shift marcos in commit 76ac8e29855b ("tty:
> serial: Cleanup the bit shift with macro"), this gap wasn't preserved.
> To avoid a break in user/kernel api of the system skip bit 3 again and
> add a placeholder comment.
> 
> Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
> ---
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: Lukas Wunner <lukas@wunner.de>
> Cc: Lino Sanfilippo <l.sanfilippo@kunbus.com>
> To: linux-serial@vger.kernel.org
> To: linux-arm-kernel@lists.infradead.org
> ---

Shouldn't this have a Fixes: tag in it?

thanks,

greg k-h

Re: [PATCH] tty: serial: Fix bit order in RS485 flag definitions

[Hugo Villeneuve]

On Thu, 18 Jan 2024 13:43:50 +0100
Christoph Niedermaier <cniedermaier@dh-electronics.com> wrote:

> Since the commit 93f3350c46fa ("RS485: fix inconsistencies in the
> meaning of some variables"), the definition for bit 3 has been removed.
> But with the switch to bit shift marcos in commit 76ac8e29855b ("tty:

marcos -> macros

Hugo Villeneuve

> serial: Cleanup the bit shift with macro"), this gap wasn't preserved.
> To avoid a break in user/kernel api of the system skip bit 3 again and
> add a placeholder comment.
> 
> Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
> ---
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
> Cc: Jiri Slaby <jirislaby@kernel.org>
> Cc: Lukas Wunner <lukas@wunner.de>
> Cc: Lino Sanfilippo <l.sanfilippo@kunbus.com>
> To: linux-serial@vger.kernel.org
> To: linux-arm-kernel@lists.infradead.org
> ---
>  include/uapi/linux/serial.h | 13 +++++++------
>  1 file changed, 7 insertions(+), 6 deletions(-)
> 
> diff --git a/include/uapi/linux/serial.h b/include/uapi/linux/serial.h
> index 9086367db043..de9b4733607e 100644
> --- a/include/uapi/linux/serial.h
> +++ b/include/uapi/linux/serial.h
> @@ -145,12 +145,13 @@ struct serial_rs485 {
>  #define SER_RS485_ENABLED		_BITUL(0)
>  #define SER_RS485_RTS_ON_SEND		_BITUL(1)
>  #define SER_RS485_RTS_AFTER_SEND	_BITUL(2)
> -#define SER_RS485_RX_DURING_TX		_BITUL(3)
> -#define SER_RS485_TERMINATE_BUS		_BITUL(4)
> -#define SER_RS485_ADDRB			_BITUL(5)
> -#define SER_RS485_ADDR_RECV		_BITUL(6)
> -#define SER_RS485_ADDR_DEST		_BITUL(7)
> -#define SER_RS485_MODE_RS422		_BITUL(8)
> +/* Placeholder for bit 3: SER_RS485_RTS_BEFORE_SEND, which isn't used anymore */
> +#define SER_RS485_RX_DURING_TX		_BITUL(4)
> +#define SER_RS485_TERMINATE_BUS		_BITUL(5)
> +#define SER_RS485_ADDRB			_BITUL(6)
> +#define SER_RS485_ADDR_RECV		_BITUL(7)
> +#define SER_RS485_ADDR_DEST		_BITUL(8)
> +#define SER_RS485_MODE_RS422		_BITUL(9)
>  
>  	__u32	delay_rts_before_send;
>  	__u32	delay_rts_after_send;
> -- 
> 2.11.0
> 
> 

RE: [PATCH] tty: serial: Fix bit order in RS485 flag definitions

[Christoph Niedermaier]

> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Sent: Thursday, January 18, 2024 3:19 PM
> On Thu, Jan 18, 2024 at 01:43:50PM +0100, Christoph Niedermaier wrote:
>> Since the commit 93f3350c46fa ("RS485: fix inconsistencies in the
>> meaning of some variables"), the definition for bit 3 has been removed.
>> But with the switch to bit shift marcos in commit 76ac8e29855b ("tty:
>> serial: Cleanup the bit shift with macro"), this gap wasn't preserved.
>> To avoid a break in user/kernel api of the system skip bit 3 again and
>> add a placeholder comment.
>>
>> Signed-off-by: Christoph Niedermaier <cniedermaier@dh-electronics.com>
>> ---
>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: Crescent CY Hsieh <crescentcy.hsieh@moxa.com>
>> Cc: Jiri Slaby <jirislaby@kernel.org>
>> Cc: Lukas Wunner <lukas@wunner.de>
>> Cc: Lino Sanfilippo <l.sanfilippo@kunbus.com>
>> To: linux-serial@vger.kernel.org
>> To: linux-arm-kernel@lists.infradead.org
>> ---
> 
> Shouldn't this have a Fixes: tag in it?

I will fix that in Version 2.


Regards
Christoph

RE: [PATCH] tty: serial: Fix bit order in RS485 flag definitions

[Christoph Niedermaier]

From: Hugo Villeneuve <hugo@hugovil.com>
Sent: Thursday, January 18, 2024 4:01 PM
> On Thu, 18 Jan 2024 13:43:50 +0100
> Christoph Niedermaier <cniedermaier@dh-electronics.com> wrote:
> 
>> Since the commit 93f3350c46fa ("RS485: fix inconsistencies in the
>> meaning of some variables"), the definition for bit 3 has been removed.
>> But with the switch to bit shift marcos in commit 76ac8e29855b ("tty:
> 
> marcos -> macros
> 

I will fix that in Version 2.

[...]

Regards
Christoph