USB: gadget: rndis: Add module parameter for DL max packets per xfer

Currently DL aggregation is supported in RNDIS driver and is set to
3 by default. And there is no support to change downlink maximum
packets per transfer at runtime through module parameter. Hence add
module parameter for DL maximum packets per transfer to change it at
runtime.

echo 6 > /sys/module/g_android/parameters/rndis_dl_max_pkt_per_xfer

To disable DL aggregation during runtime,

echo 1 > /sys/module/g_android/parameters/rndis_dl_max_pkt_per_xfer

Change-Id: I3a1d0bc97358e2b6f233df7ae8725fb507de50db
Signed-off-by: Xerox Lin <xerox_lin@htc.com>
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>

diff --git a/drivers/usb/gadget/function/f_rndis.c b/drivers/usb/gadget/function/f_rndis.c
index 635bbbbd063952245e55c6a563926cbef8c390e4..2758522180f392eabfa30f7eb991538b51097bb9 100644 (file)
--- a/drivers/usb/gadget/function/f_rndis.c
+++ b/drivers/usb/gadget/function/f_rndis.c
@@ -70,10 +70,10 @@
  *   - MS-Windows drivers sometimes emit undocumented requests.
  */
 
-static bool rndis_multipacket_dl_disable;
-module_param(rndis_multipacket_dl_disable, bool, S_IRUGO|S_IWUSR);
-MODULE_PARM_DESC(rndis_multipacket_dl_disable,
-       "Disable RNDIS Multi-packet support in DownLink");
+static unsigned int rndis_dl_max_pkt_per_xfer = 3;
+module_param(rndis_dl_max_pkt_per_xfer, uint, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(rndis_dl_max_pkt_per_xfer,
+       "Maximum packets per transfer for DL aggregation");
 
 static unsigned int rndis_ul_max_pkt_per_xfer = 3;
 module_param(rndis_ul_max_pkt_per_xfer, uint, S_IRUGO | S_IWUSR);
@@ -480,7 +480,7 @@ static void rndis_command_complete(struct usb_ep *ep, struct usb_request *req)
                                __func__, buf->MaxTransferSize,
                                rndis->port.multi_pkt_xfer ? "enabled" :
                                                            "disabled");
-               if (rndis_multipacket_dl_disable)
+               if (rndis_dl_max_pkt_per_xfer <= 1)
                        rndis->port.multi_pkt_xfer = 0;
        }
 //     spin_unlock(&dev->lock);
@@ -1006,6 +1006,7 @@ static struct usb_function *rndis_alloc(struct usb_function_instance *fi)
        rndis->port.wrap = rndis_add_header;
        rndis->port.unwrap = rndis_rm_hdr;
        rndis->port.ul_max_pkts_per_xfer = rndis_ul_max_pkt_per_xfer;
+       rndis->port.dl_max_pkts_per_xfer = rndis_dl_max_pkt_per_xfer;
 
        rndis->port.func.name = "rndis";
        /* descriptors are per-instance copies */

diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
index 69bf03e046031fa739a388f43427ab40aaf1ac45..e39880a654cc4fc095b5834a25d92814a5bf180b 100644 (file)
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -79,6 +79,7 @@ struct eth_dev {
 
        unsigned                header_len;
        unsigned                ul_max_pkts_per_xfer;
+       unsigned                dl_max_pkts_per_xfer;
        struct sk_buff          *(*wrap)(struct gether *, struct sk_buff *skb);
        int                     (*unwrap)(struct gether *,
                                                struct sk_buff *skb,
@@ -581,7 +582,7 @@ static void alloc_tx_buffer(struct eth_dev *dev)
        struct list_head        *act;
        struct usb_request      *req;
 
-       dev->tx_req_bufsize = (TX_SKB_HOLD_THRESHOLD *
+       dev->tx_req_bufsize = (dev->dl_max_pkts_per_xfer *
                                (dev->net->mtu
                                + sizeof(struct ethhdr)
                                /* size of rndis_packet_msg_type */
@@ -699,7 +700,7 @@ static netdev_tx_t eth_start_xmit(struct sk_buff *skb,
                dev_kfree_skb_any(skb);
 
                spin_lock_irqsave(&dev->req_lock, flags);
-               if (dev->tx_skb_hold_count < TX_SKB_HOLD_THRESHOLD) {
+               if (dev->tx_skb_hold_count < dev->dl_max_pkts_per_xfer) {
                        if (dev->no_tx_req_used > TX_REQ_THRESHOLD) {
                                list_add(&req->list, &dev->tx_reqs);
                                spin_unlock_irqrestore(&dev->req_lock, flags);
@@ -1248,6 +1249,7 @@ struct net_device *gether_connect(struct gether *link)
                dev->unwrap = link->unwrap;
                dev->wrap = link->wrap;
                dev->ul_max_pkts_per_xfer = link->ul_max_pkts_per_xfer;
+               dev->dl_max_pkts_per_xfer = link->dl_max_pkts_per_xfer;
 
                spin_lock(&dev->lock);
                dev->tx_skb_hold_count = 0;

diff --git a/drivers/usb/gadget/function/u_ether.h b/drivers/usb/gadget/function/u_ether.h
index 7914b4b1ce6cad9a62d5900a418b2410a3875818..e9fd14b461026e1b878f4d1c45c7ac00d0ad704f 100644 (file)
--- a/drivers/usb/gadget/function/u_ether.h
+++ b/drivers/usb/gadget/function/u_ether.h
@@ -74,8 +74,7 @@ struct gether {
        u32                             fixed_out_len;
        u32                             fixed_in_len;
        unsigned                ul_max_pkts_per_xfer;
-/* Max number of SKB packets to be used to create Multi Packet RNDIS */
-#define TX_SKB_HOLD_THRESHOLD          3
+       unsigned                dl_max_pkts_per_xfer;
        bool                            multi_pkt_xfer;
        bool                            supports_multi_frame;
        struct sk_buff                  *(*wrap)(struct gether *port,