bas_gigaset: collapse CR/LF at end of AT response

Copy the mechanism from ser_/usb_gigaset to avoid producing
spurious empty responses for CR/LF sequences from the device.
Add a comment in all drivers documenting that behaviour.
Correct an off by one error that might result in a one byte
buffer overflow when receiving an unexpectedly long reply.

Impact: minor bugfix
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index e963a6c2e86d..c9ccf7de2275 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -38,7 +38,7 @@
 #define GIG_COMPAT  {0, 4, 0, 0}
 
 #define MAX_REC_PARAMS 10       /* Max. number of params in response string */
-#define MAX_RESP_SIZE 512       /* Max. size of a response string */
+#define MAX_RESP_SIZE 511       /* Max. size of a response string */
 
 #define MAX_EVENTS 64           /* size of event queue */
 
@@ -498,7 +498,7 @@ struct cardstate {
         spinlock_t ev_lock;
 
         /* current modem response */
-        unsigned char respdata[MAX_RESP_SIZE];
+        unsigned char respdata[MAX_RESP_SIZE+1];
         unsigned cbytes;
 
         /* private data of hardware drivers */