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, 10 insertions, 17 deletions

diff --git a/drivers/net/wireless/libertas/dev.h b/drivers/net/wireless/libertas/dev.h
index 1e6bae80396b..0d9edb9b11f5 100644
--- a/drivers/net/wireless/libertas/dev.h
+++ b/drivers/net/wireless/libertas/dev.h
@@ -129,10 +129,6 @@ struct lbs_private {
         u32 bbp_offset;
         u32 rf_offset;
 
-        /** Upload length */
-        u32 upld_len;
-        /* Upload buffer */
-        u8 upld_buf[LBS_UPLD_SIZE];
         /* Download sent:
            bit0 1/0=data_sent/data_tx_done,
            bit1 1/0=cmd_sent/cmd_tx_done,
@@ -155,21 +151,16 @@ struct lbs_private {
 
         /** Hardware access */
         int (*hw_host_to_card) (struct lbs_private *priv, u8 type, u8 *payload, u16 nb);
-        int (*hw_get_int_status) (struct lbs_private *priv, u8 *);
-        int (*hw_read_event_cause) (struct lbs_private *);
 
         /* Wake On LAN */
         uint32_t wol_criteria;
         uint8_t wol_gpio;
         uint8_t wol_gap;
 
-        /* was struct lbs_adapter from here... */
-
         /** Wlan adapter data structure*/
         /** STATUS variables */
         u32 fwrelease;
         u32 fwcapinfo;
-        /* protected with big lock */
 
         struct mutex lock;
 
@@ -181,7 +172,6 @@ struct lbs_private {
 
         /** command-related variables */
         u16 seqnum;
-        /* protected by big lock */
 
         struct cmd_ctrl_node *cmd_array;
         /** Current command */
@@ -194,12 +184,17 @@ struct lbs_private {
         struct list_head cmdpendingq;
 
         wait_queue_head_t cmd_pending;
-        /* command related variables protected by priv->driver_lock */
 
-        /** Async and Sync Event variables */
-        u32 intcounter;
-        u32 eventcause;
-        u8 nodename[16];        /* nickname */
+        /* Command responses sent from the hardware to the driver */
+        u8 resp_idx;
+        u8 resp_buf[2][LBS_UPLD_SIZE];
+        u32 resp_len[2];
+
+        /* Events sent from hardware to driver */
+        struct kfifo *event_fifo;
+
+        /* nickname */
+        u8 nodename[16];
 
         /** spin locks */
         spinlock_t driver_lock;
@@ -209,8 +204,6 @@ struct lbs_private {
         int nr_retries;
         int cmd_timed_out;
 
-        u8 hisregcpy;
-
         /** current ssid/bssid related parameters*/
         struct current_bss_params curbssparams;