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From: Brian Inglis <Brian.Inglis@SystematicSw.ab.ca>
To: cygwin-patches@cygwin.com
Subject: Re: fhandler_serial.cc: MARK and SPACE parity for serial port
Date: Thu, 28 Jan 2021 10:17:03 -0700	[thread overview]
Message-ID: <6c0a481b-b6fb-0a7e-66ef-36e1941397bb@SystematicSw.ab.ca> (raw)
In-Reply-To: <20210128101429.GX4393@calimero.vinschen.de>

On 2021-01-28 03:14, Corinna Vinschen via Cygwin-patches wrote:
> On Jan 28 11:08, Corinna Vinschen via Cygwin-patches wrote:
>> Hi Marek,
>> thanks for the patch.  [...]
>>> index 17e8d83a3..933851c21 100644
>>> --- a/winsup/cygwin/include/sys/termios.h
>>> +++ b/winsup/cygwin/include/sys/termios.h
>>> @@ -185,6 +185,7 @@ POSIX commands */
>>>   #define PARODD 0x00200
>>>   #define HUPCL 0x00400
>>>   #define CLOCAL 0x00800
>>> +#define CMSPAR  0x40000000 /* Mark or space (stick) parity.  */
> 
> Why did you choose such a big value here?  Wouldn't it be nicer just to
> follow up with
> 
>    #define CMSPAR 0x10000
> 
> or am I missing something here?

GLIBC/Linux compatibility:
https://sourceware.org/git/?p=glibc.git&a=search&h=HEAD&st=grep&s=define+CMSPAR

sysdeps/unix/sysv/linux/alpha/bits/termios-baud.h	
   23 #ifdef __USE_MISC
   24 # define CBAUD  0000037
   25 # define CBAUDEX 0000000
   26 # define CMSPAR   010000000000          /* mark or space (stick) parity */
   27 # define CRTSCTS  020000000000          /* flow control */
   28 #endif
sysdeps/unix/sysv/linux/bits/termios-baud.h	
   23 #ifdef __USE_MISC
   24 # define CBAUD   000000010017 /* Baud speed mask (not in POSIX).  */
   25 # define CBAUDEX 000000010000 /* Extra baud speed mask, included in CBAUD.
   26                                  (not in POSIX).  */
   27 # define CIBAUD  002003600000 /* Input baud rate (not used).  */
   28 # define CMSPAR  010000000000 /* Mark or space (stick) parity.  */
   29 # define CRTSCTS 020000000000 /* Flow control.  */
   30 #endif
sysdeps/unix/sysv/linux/powerpc/bits/termios-baud.h	
   23 #ifdef __USE_MISC
   24 # define CBAUD  0000377
   25 # define CBAUDEX 0000020
   26 # define CMSPAR   010000000000          /* mark or space (stick) parity */
   27 # define CRTSCTS  020000000000          /* flow control */
   28 #endif
sysdeps/unix/sysv/linux/sparc/bits/termios-baud.h	
   23 #ifdef __USE_MISC
   24 # define CBAUD   0x0000100f
   25 # define CBAUDEX 0x00001000
   26 # define CIBAUD  0x100f0000     /* input baud rate (not used) */
   27 # define CMSPAR  0x40000000     /* mark or space (stick) parity */
   28 # define CRTSCTS 0x80000000     /* flow control */
   29 #endif

> Also, on second thought I think CMSPAR should follow CRTSCTS, a few
> lines below, because of its numerical value higher than CRTSCTS.

GLIBC/Linux normally has it lower:
$ grep -C2 'define\s\+CMSPAR' /usr/include/**/*.h
/usr/include/asm-generic/termbits.h:
#define  B4000000 0010017
#define CIBAUD	  002003600000	/* input baud rate */
#define CMSPAR	  010000000000	/* mark or space (stick) parity */
#define CRTSCTS	  020000000000	/* flow control */

--
/usr/include/i386-linux-gnu/bits/termios.h:
#ifdef __USE_MISC
# define CIBAUD	  002003600000		/* input baud rate (not used) */
# define CMSPAR   010000000000		/* mark or space (stick) parity */
# define CRTSCTS  020000000000		/* flow control */
#endif
-- 
Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

This email may be disturbing to some readers as it contains
too much technical detail. Reader discretion is advised.
[Data in binary units and prefixes, physical quantities in SI.]

  reply	other threads:[~2021-01-28 17:17 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-27 20:30 Marek Smetana
2021-01-28 10:08 ` Corinna Vinschen
2021-01-28 10:14   ` Corinna Vinschen
2021-01-28 17:17     ` Brian Inglis [this message]
2021-01-28 18:45       ` Brian Inglis
2021-01-29 22:06     ` Marek Smetana
2021-02-01  9:40       ` Corinna Vinschen
2021-02-01 21:26         ` Marek Smetana
2021-02-02  5:28           ` Brian Inglis
2021-02-02  9:44           ` Corinna Vinschen

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