[patch] serial line

[Diego Roversi]

Hello, 

  the first patch allow programs to set the serial line speed at 57600 and
115200.

diff -ur hurd-20010817/term/devio.c hurd-20010817.new/term/devio.c
--- hurd-20010817/term/devio.c  Sat Mar 18 19:37:21 2000
+++ hurd-20010817.new/term/devio.c      Sat Oct  6 11:50:58 2001
@@ -164,10 +164,16 @@
       *bspeed = B9600;
       break;
     case 19200:
-      *bspeed = EXTA;
+      *bspeed = B19200;
       break;
     case 38400:
-      *bspeed = EXTB;
+      *bspeed = B38400;
+      break;
+    case 57600:
+      *bspeed = B57600;
+      break;
+    case 115200:
+      *bspeed = B115200;
       break;
     default:
       return -1;
@@ -210,10 +216,15 @@
       return 4800;
     case B9600:
       return 9600;
-    case EXTA:
+    case B19200:
       return 19200;
-    case EXTB:
+    case B38400:
       return 38400;
+    case B57600:
+      return 57600;
+    case B115200:
+      return 115200;
+       
     }
 }
 
The second patch is quite experimental, and allow to transfer at high speed
continuisly without loosing data. There is still two problems: the first one
is that sometime sending data block after about 30k-40k of sustained
transfert. Receiving works fine. The second one is that I don't know exactly
why my patch improves serial line handling. BTW this is the patch:

diff -ur gnumach-20010918/device/chario.c gnumach-20010918.new/device/chario.c
--- gnumach-20010918/device/chario.c    Sun Apr 29 22:26:01 2001
+++ gnumach-20010918.new/device/chario.c        Tue Oct  9 22:45:58 2001
@@ -122,8 +122,8 @@
   pdma_timeouts[B2400] = _PR(240);
   pdma_timeouts[B4800] = _PR(480);
   pdma_timeouts[B9600] = _PR(960);
-  pdma_timeouts[EXTA]  = _PR(1440); /* >14400 baud */
-  pdma_timeouts[EXTB]  = _PR(1920); /* >19200 baud */
+  pdma_timeouts[B19200]  = _PR(1920); /* >14400 baud */
+  pdma_timeouts[B38400]  = _PR(3840); /* >19200 baud */
   pdma_timeouts[B57600] = _PR(5760);
   pdma_timeouts[B115200] = _PR(11520);
 
@@ -143,13 +143,23 @@
   pdma_water_mark[B1800] = _PR(180);
   pdma_water_mark[B2400] = _PR(240);
   pdma_water_mark[B4800] = _PR(480);
+  pdma_water_mark[B9600] = _PR(960);
+  pdma_water_mark[B19200] = _PR(1920);
+#undef _PR
+#define _PR(X) (0.10 * X)   
+  pdma_water_mark[B38400] = 192;
+  pdma_water_mark[B57600] = 96;
+  pdma_water_mark[B115200] = 64;
+   
+#if 0   
   i = tty_inq_size/2;
   pdma_water_mark[B9600] = i;
   pdma_water_mark[EXTA]  = i; /* >14400 baud */
   pdma_water_mark[EXTB]  = i; /* >19200 baud */
   pdma_water_mark[B57600] = i;
   pdma_water_mark[B115200] = i;
-
+#endif
+   
   return;
 }
 

I don't understand what is this pdma stuff (serial port usualy don'use dma
on PC), but IHMO water_mark is how much incoming data is collected before
being processed. I don't understand why water_mark must decrease at higher
speed. BTW the values for speed of 38400 or greater was found out with some
experiments.

That's all for the moment...

-- 
Saluti / Regards

Diego Roversi | diegor at maganet.net
              | diegor at tiscalinet.it