mISDN: Allow to set a minimum length for transparent data

If the FIFO of the card is small, many short messages are queued up to
the upper layers and the userspace. This change allows the applications
to set a minimum datalen they want from the drivers.
Create a common control function to avoid code duplication in each
driver.

Signed-off-by: Karsten Keil <kkeil@linux-pingi.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 8 insertions, 1 deletions

diff --git a/include/linux/mISDNif.h b/include/linux/mISDNif.h
index ce6e613dff4c..246a3529ecf6 100644
--- a/include/linux/mISDNif.h
+++ b/include/linux/mISDNif.h
@@ -37,7 +37,7 @@
  */
 #define MISDN_MAJOR_VERSION     1
 #define MISDN_MINOR_VERSION     1
-#define MISDN_RELEASE           28
+#define MISDN_RELEASE           29
 
 /* primitives for information exchange
  * generell format
@@ -365,6 +365,7 @@ clear_channelmap(u_int nr, u_char *map)
 #define MISDN_CTRL_LOOP                 0x0001
 #define MISDN_CTRL_CONNECT              0x0002
 #define MISDN_CTRL_DISCONNECT           0x0004
+#define MISDN_CTRL_RX_BUFFER            0x0008
 #define MISDN_CTRL_PCMCONNECT           0x0010
 #define MISDN_CTRL_PCMDISCONNECT        0x0020
 #define MISDN_CTRL_SETPEER              0x0040
@@ -387,6 +388,12 @@ clear_channelmap(u_int nr, u_char *map)
 #define MISDN_CTRL_HFC_WD_INIT          0x4009
 #define MISDN_CTRL_HFC_WD_RESET         0x400A
 
+/* special RX buffer value for MISDN_CTRL_RX_BUFFER request.p1 is the minimum
+ * buffer size request.p2 the maximum. Using  MISDN_CTRL_RX_SIZE_IGNORE will
+ * not change the value, but still read back the actual stetting.
+ */
+#define MISDN_CTRL_RX_SIZE_IGNORE       -1
+
 /* socket options */
 #define MISDN_TIME_STAMP                0x0001