libertas: convert libertas driver to use an event/cmdresp queue

This patch (co-developed by Dan Williams and Holger Schurig) uses a kfifo
object for events and a swapping buffer scheme for the command response to
preserve the zero-copy semantics of the CF driver and keep memory usage low.
The main thread should only ever touch the buffer indexed by priv->resp_idx,
while the interface code is free to write to the second buffer, then swap
priv->resp_idx under the driver spinlock.  The firmware specs only permit
one in-flight command, so there will only ever be one command response to
process at a time.

Signed-off-by: Holger Schurig <hs4233@mail.mn-solutions.de>
Signed-off-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 7 insertions, 16 deletions

diff --git a/drivers/net/wireless/libertas/cmdresp.c b/drivers/net/wireless/libertas/cmdresp.c
index 245d3c3a9274..5abecb7673e6 100644
--- a/drivers/net/wireless/libertas/cmdresp.c
+++ b/drivers/net/wireless/libertas/cmdresp.c
@@ -384,7 +384,7 @@ static inline int handle_cmd_response(struct lbs_private *priv,
         return ret;
 }
 
-int lbs_process_rx_command(struct lbs_private *priv)
+int lbs_process_command_response(struct lbs_private *priv, u8 *data, u32 len)
 {
         uint16_t respcmd, curcmd;
         struct cmd_header *resp;
@@ -404,14 +404,14 @@ int lbs_process_rx_command(struct lbs_private *priv)
                 goto done;
         }
 
-        resp = (void *)priv->upld_buf;
+        resp = (void *)data;
         curcmd = le16_to_cpu(priv->cur_cmd->cmdbuf->command);
         respcmd = le16_to_cpu(resp->command);
         result = le16_to_cpu(resp->result);
 
         lbs_deb_cmd("CMD_RESP: response 0x%04x, seq %d, size %d\n",
-                     respcmd, le16_to_cpu(resp->seqnum), priv->upld_len);
-        lbs_deb_hex(LBS_DEB_CMD, "CMD_RESP", (void *) resp, priv->upld_len);
+                     respcmd, le16_to_cpu(resp->seqnum), len);
+        lbs_deb_hex(LBS_DEB_CMD, "CMD_RESP", (void *) resp, len);
 
         if (resp->seqnum != priv->cur_cmd->cmdbuf->seqnum) {
                 lbs_pr_info("Received CMD_RESP with invalid sequence %d (expected %d)\n",
@@ -569,18 +569,13 @@ static int lbs_send_confirmwake(struct lbs_private *priv)
         return ret;
 }
 
-int lbs_process_event(struct lbs_private *priv)
+int lbs_process_event(struct lbs_private *priv, u32 event)
 {
         int ret = 0;
-        u32 eventcause;
 
         lbs_deb_enter(LBS_DEB_CMD);
 
-        spin_lock_irq(&priv->driver_lock);
-        eventcause = priv->eventcause >> SBI_EVENT_CAUSE_SHIFT;
-        spin_unlock_irq(&priv->driver_lock);
-
-        switch (eventcause) {
+        switch (event) {
         case MACREG_INT_CODE_LINK_SENSED:
                 lbs_deb_cmd("EVENT: link sensed\n");
                 break;
@@ -696,14 +691,10 @@ int lbs_process_event(struct lbs_private *priv)
                 break;
 
         default:
-                lbs_pr_alert("EVENT: unknown event id %d\n", eventcause);
+                lbs_pr_alert("EVENT: unknown event id %d\n", event);
                 break;
         }
 
-        spin_lock_irq(&priv->driver_lock);
-        priv->eventcause = 0;
-        spin_unlock_irq(&priv->driver_lock);
-
         lbs_deb_leave_args(LBS_DEB_CMD, "ret %d", ret);
         return ret;
 }