Reduce TX retry timeout and re-read buffer status

Detail:
Under certain circumstances, especially iMx->iMx with sharefs, with its default
window value of 2, it was possible for all tx buffers to be left full.
The timeout loop failed to refresh the buffer status. Now resolved.
Admin:
tested iMx<->iMx

Version 0.27. Tagged as 'EtherTH-0_27'

VersionASM

@@ -11,13 +11,13 @@
                         GBLS    Module_HelpVersion
                         GBLS    Module_ComponentName
                         GBLS    Module_ComponentPath
-Module_MajorVersion     SETS    "0.26"
-Module_Version          SETA    26
+Module_MajorVersion     SETS    "0.27"
+Module_Version          SETA    27
 Module_MinorVersion     SETS    ""
-Module_Date             SETS    "11 Mar 2017"
-Module_ApplicationDate  SETS    "11-Mar-17"
+Module_Date             SETS    "27 Apr 2017"
+Module_ApplicationDate  SETS    "27-Apr-17"
 Module_ComponentName    SETS    "EtherTH"
 Module_ComponentPath    SETS    "mixed/RiscOS/Sources/Networking/Ethernet/EtherTH"
-Module_FullVersion      SETS    "0.26"
-Module_HelpVersion      SETS    "0.26 (11 Mar 2017)"
+Module_FullVersion      SETS    "0.27"
+Module_HelpVersion      SETS    "0.27 (27 Apr 2017)"
                         END

VersionNum

-/* (0.26)
+/* (0.27)
  *
  * This file is automatically maintained by srccommit, do not edit manually.
  * Last processed by srccommit version: 1.1.
  *
  */
-#define Module_MajorVersion_CMHG        0.26
+#define Module_MajorVersion_CMHG        0.27
 #define Module_MinorVersion_CMHG        
-#define Module_Date_CMHG                11 Mar 2017
+#define Module_Date_CMHG                27 Apr 2017
 
-#define Module_MajorVersion             "0.26"
-#define Module_Version                  26
+#define Module_MajorVersion             "0.27"
+#define Module_Version                  27
 #define Module_MinorVersion             ""
-#define Module_Date                     "11 Mar 2017"
+#define Module_Date                     "27 Apr 2017"
 
-#define Module_ApplicationDate          "11-Mar-17"
+#define Module_ApplicationDate          "27-Apr-17"
 
 #define Module_ComponentName            "EtherTH"
 #define Module_ComponentPath            "mixed/RiscOS/Sources/Networking/Ethernet/EtherTH"
 
-#define Module_FullVersion              "0.26"
-#define Module_HelpVersion              "0.26 (11 Mar 2017)"
-#define Module_LibraryVersionInfo       "0:26"
+#define Module_FullVersion              "0.27"
+#define Module_HelpVersion              "0.27 (27 Apr 2017)"
+#define Module_LibraryVersionInfo       "0:27"

c/device

@@ -559,14 +559,15 @@ _kernel_oserror* device_transmit(device_t* d, dci_TransmitArgs_t* args)
                 {
                         /*
                          * Buffer full
-                         * Wait up to 0.1 secs for a buffer to clear so that we don't have to
+                         * Wait up to 0.015 secs for a buffer to clear so that we don't have to
                          * discard the packet and suffer a retry.
                          */
                         device_setReg(d, ENET_TDAR, ENET_TDAR__TDAR); /* just in case its not set */
                         int i;
-                        for (i = 10000; i; i--)
+                        for (i = 150; i; i--)
                         {
                                 utils_delay_us(10);
+                                status = d->tx_ring_ptr->status;
                                 if ((status & TXBD_STATUS__R) == 0) break;
                         }
                         if (i == 0) break; /* No use - will have to discard it */