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

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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>
This commit is contained in:
Holger Schurig
2008-04-01 14:50:43 +02:00
committed by John W. Linville
parent 98dd6a5759
commit 7919b89c82
13 changed files with 270 additions and 384 deletions
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25
drivers/net/wireless/libertas/cmd.c
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@@ -4,6 +4,7 @@
*/
#include <net/iw_handler.h>
#include <linux/kfifo.h>
#include "host.h"
#include "hostcmd.h"
#include "decl.h"
@@ -1829,15 +1830,20 @@ static void lbs_send_confirmsleep(struct lbs_private *priv)
ret = priv->hw_host_to_card(priv, MVMS_CMD, (u8 *) &confirm_sleep,
sizeof(confirm_sleep));
if (ret) {
lbs_pr_alert("confirm_sleep failed\n");
} else {
spin_lock_irqsave(&priv->driver_lock, flags);
if (!priv->intcounter)
priv->psstate = PS_STATE_SLEEP;
spin_unlock_irqrestore(&priv->driver_lock, flags);
goto out;
}
spin_lock_irqsave(&priv->driver_lock, flags);
/* If nothing to do, go back to sleep (?) */
if (!__kfifo_len(priv->event_fifo) && !priv->resp_len[priv->resp_idx])
priv->psstate = PS_STATE_SLEEP;
spin_unlock_irqrestore(&priv->driver_lock, flags);
out:
lbs_deb_leave(LBS_DEB_HOST);
}
@@ -1899,13 +1905,16 @@ void lbs_ps_confirm_sleep(struct lbs_private *priv)
}
spin_lock_irqsave(&priv->driver_lock, flags);
/* In-progress command? */
if (priv->cur_cmd) {
allowed = 0;
lbs_deb_host("cur_cmd was set\n");
}
if (priv->intcounter > 0) {
/* Pending events or command responses? */
if (__kfifo_len(priv->event_fifo) || priv->resp_len[priv->resp_idx]) {
allowed = 0;
lbs_deb_host("intcounter %d\n", priv->intcounter);
lbs_deb_host("pending events or command responses\n");
}
spin_unlock_irqrestore(&priv->driver_lock, flags);