[PATCH 3/4] backports: cw1200 utilizes kthreads for <= 2.6.35

[Solomon Peachy <pizza@xxxxxxxxxxxx>]

The new workqueue APIs in 2.6.36 allowed us to scrap the old kthread worker
that had been used; unfortunately the backported API isn't complete so
in order to support older kernels, resurrect this patch.

Signed-off-by: Solomon Peachy <pizza@xxxxxxxxxxxx>
---
 .../75-cw1200-workqueues/cw1200_workqueues.patch   | 133 +++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 patches/collateral-evolutions/network/75-cw1200-workqueues/cw1200_workqueues.patch

diff --git a/patches/collateral-evolutions/network/75-cw1200-workqueues/cw1200_workqueues.patch b/patches/collateral-evolutions/network/75-cw1200-workqueues/cw1200_workqueues.patch
new file mode 100644
index 0000000..3bf3197
--- /dev/null
+++ b/patches/collateral-evolutions/network/75-cw1200-workqueues/cw1200_workqueues.patch
@@ -0,0 +1,133 @@
+diff --git a/drivers/net/wireless/cw1200/bh.c b/drivers/net/wireless/cw1200/bh.c
+index c1ec2a4..5dcbb4e 100644
+--- a/drivers/net/wireless/cw1200/bh.c
++++ b/drivers/net/wireless/cw1200/bh.c
+@@ -48,16 +48,22 @@ enum cw1200_bh_pm_state {
+ typedef int (*cw1200_wsm_handler)(struct cw1200_common *priv,
+ 	u8 *data, size_t size);
+ 
++#ifndef CW1200_USE_COMPAT_KTHREAD
+ static void cw1200_bh_work(struct work_struct *work)
+ {
+ 	struct cw1200_common *priv =
+ 	container_of(work, struct cw1200_common, bh_work);
+ 	cw1200_bh(priv);
+ }
++#endif
+ 
+ int cw1200_register_bh(struct cw1200_common *priv)
+ {
+ 	int err = 0;
++#ifdef CW1200_USE_COMPAT_KTHREAD
++	struct sched_param param = { .sched_priority = 1 };
++	BUG_ON(priv->bh_thread);
++#else
+ 	/* Realtime workqueue */
+ 	priv->bh_workqueue = alloc_workqueue("cw1200_bh",
+ 				WQ_MEM_RECLAIM | WQ_HIGHPRI
+@@ -67,6 +73,7 @@ int cw1200_register_bh(struct cw1200_common *priv)
+ 		return -ENOMEM;
+ 
+ 	INIT_WORK(&priv->bh_work, cw1200_bh_work);
++#endif
+ 
+ 	pr_debug("[BH] register.\n");
+ 
+@@ -81,20 +88,44 @@ int cw1200_register_bh(struct cw1200_common *priv)
+ 	init_waitqueue_head(&priv->bh_wq);
+ 	init_waitqueue_head(&priv->bh_evt_wq);
+ 
++#ifdef CW1200_USE_COMPAT_KTHREAD
++	priv->bh_thread = kthread_create(&cw1200_bh, priv, "cw1200_bh");
++	if (IS_ERR(priv->bh_thread)) {
++		err = PTR_ERR(priv->bh_thread);
++		priv->bh_thread = NULL;
++	} else {
++		WARN_ON(sched_setscheduler(priv->bh_thread,
++					   SCHED_FIFO, &param));
++		wake_up_process(priv->bh_thread);
++	}
++#else
+ 	err = !queue_work(priv->bh_workqueue, &priv->bh_work);
+ 	WARN_ON(err);
++#endif
++
+ 	return err;
+ }
+ 
+ void cw1200_unregister_bh(struct cw1200_common *priv)
+ {
++#ifdef CW1200_USE_COMPAT_KTHREAD
++	struct task_struct *thread = priv->bh_thread;
++	if (WARN_ON(!thread))
++		return;
++#endif
++
+ 	atomic_add(1, &priv->bh_term);
+ 	wake_up(&priv->bh_wq);
+ 
++#ifdef CW1200_USE_COMPAT_KTHREAD
++	kthread_stop(thread);
++	priv->bh_thread = NULL;
++#else
+ 	flush_workqueue(priv->bh_workqueue);
+ 
+ 	destroy_workqueue(priv->bh_workqueue);
+ 	priv->bh_workqueue = NULL;
++#endif
+ 
+ 	pr_debug("[BH] unregistered.\n");
+ }
+@@ -614,6 +645,16 @@ static int cw1200_bh(void *arg)
+ 		pr_err("[BH] Fatal error, exiting.\n");
+ 		priv->bh_error = 1;
+ 		/* TODO: schedule_work(recovery) */
++#ifdef CW1200_USE_COMPAT_KTHREAD
++		for (;;) {
++			int status = wait_event_interruptible(priv->bh_wq, ({
++				term = atomic_xchg(&priv->bh_term, 0);
++				(term);
++			}));
++		if (status || term)
++			break;
++	}
++#endif
+ 	}
+ 	return 0;
+ }
+diff --git a/drivers/net/wireless/cw1200/cw1200.h b/drivers/net/wireless/cw1200/cw1200.h
+index 1ad7d36..300dbbb 100644
+--- a/drivers/net/wireless/cw1200/cw1200.h
++++ b/drivers/net/wireless/cw1200/cw1200.h
+@@ -23,12 +23,18 @@
+ #include <linux/workqueue.h>
+ #include <net/mac80211.h>
+ 
++#include <linux/version.h>
++
+ #include "queue.h"
+ #include "wsm.h"
+ #include "scan.h"
+ #include "txrx.h"
+ #include "pm.h"
+ 
++#if (LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 36))
++#define CW1200_USE_COMPAT_KTHREAD
++#endif
++
+ /* Forward declarations */
+ struct hwbus_ops;
+ struct task_struct;
+@@ -190,8 +196,12 @@ struct cw1200_common {
+ 	atomic_t			bh_term;
+ 	atomic_t			bh_suspend;
+ 
++#ifdef CW1200_USE_COMPAT_KTHREAD
++	struct task_struct              *bh_thread;
++#else
+ 	struct workqueue_struct         *bh_workqueue;
+ 	struct work_struct              bh_work;
++#endif
+ 
+ 	int				bh_error;
+ 	wait_queue_head_t		bh_wq;
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe backports" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html