net: cdc_ncm: use sane defaults for rx/tx buffers
Lots of devices request much larger buffers than reasonable. This
cause real problems for users of hosts with limited resources.
Reducing the default buffer size to 16kB for such devices is
a reasonable trade-off between allowing them to aggregate traffic
and avoiding memory exhaustion on resource restrained hosts.
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/usb/cdc_ncm.h b/include/linux/usb/cdc_ncm.h
index 88d2d7f..cde5067 100644
--- a/include/linux/usb/cdc_ncm.h
+++ b/include/linux/usb/cdc_ncm.h
@@ -52,6 +52,10 @@
#define CDC_NCM_NTB_MAX_SIZE_TX 32768 /* bytes */
#define CDC_NCM_NTB_MAX_SIZE_RX 32768 /* bytes */
+/* Initial NTB length */
+#define CDC_NCM_NTB_DEF_SIZE_TX 16384 /* bytes */
+#define CDC_NCM_NTB_DEF_SIZE_RX 16384 /* bytes */
+
/* Minimum value for MaxDatagramSize, ch. 6.2.9 */
#define CDC_NCM_MIN_DATAGRAM_SIZE 1514 /* bytes */