V4L/DVB (5208): Kthread API conversion for dvb_frontend and av7110

dvb kernel_thread to kthread API port.  
It is running fine here, including module load/unload and software suspend
(which doesn't work as expected with or without this patch :).
I didn't convert the dvb_ca_en50221 as I do not have such an interface, but
if the conversion process is fine with the v4l-dvb maintainers, it should not
be a problem to send a patch for that too ...
Acked-by: Oliver Endriss <o.endriss@gmx.de>

Signed-off-by: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Oliver Endriss <o.endriss@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

3 files changed, 37 insertions, 62 deletions

diff --git a/drivers/media/dvb/dvb-core/dvb_frontend.c b/drivers/media/dvb/dvb-core/dvb_frontend.c
index 7c42d53a1cc7..470ae167beb9 100644
--- a/drivers/media/dvb/dvb-core/dvb_frontend.c
+++ b/drivers/media/dvb/dvb-core/dvb_frontend.c
@@ -36,6 +36,7 @@
 #include <linux/list.h>
 #include <linux/freezer.h>
 #include <linux/jiffies.h>
+#include <linux/kthread.h>
 #include <asm/processor.h>
 
 #include "dvb_frontend.h"
@@ -100,7 +101,7 @@ struct dvb_frontend_private {
         struct semaphore sem;
         struct list_head list_head;
         wait_queue_head_t wait_queue;
-        pid_t thread_pid;
+        struct task_struct *thread;
         unsigned long release_jiffies;
         unsigned int exit;
         unsigned int wakeup;
@@ -508,19 +509,11 @@ static int dvb_frontend_thread(void *data)
         struct dvb_frontend *fe = data;
         struct dvb_frontend_private *fepriv = fe->frontend_priv;
         unsigned long timeout;
-        char name [15];
         fe_status_t s;
         struct dvb_frontend_parameters *params;
 
         dprintk("%s\n", __FUNCTION__);
 
-        snprintf (name, sizeof(name), "kdvb-fe-%i", fe->dvb->num);
-
-        lock_kernel();
-        daemonize(name);
-        sigfillset(&current->blocked);
-        unlock_kernel();
-
         fepriv->check_wrapped = 0;
         fepriv->quality = 0;
         fepriv->delay = 3*HZ;
@@ -534,14 +527,16 @@ static int dvb_frontend_thread(void *data)
                 up(&fepriv->sem);           /* is locked when we enter the thread... */
 
                 timeout = wait_event_interruptible_timeout(fepriv->wait_queue,
-                                                           dvb_frontend_should_wakeup(fe),
-                                                           fepriv->delay);
-                if (0 != dvb_frontend_is_exiting(fe)) {
+                        dvb_frontend_should_wakeup(fe) || kthread_should_stop(),
+                        fepriv->delay);
+
+                if (kthread_should_stop() || dvb_frontend_is_exiting(fe)) {
                         /* got signal or quitting */
                         break;
                 }
 
-                try_to_freeze();
+                if (try_to_freeze())
+                        continue;
 
                 if (down_interruptible(&fepriv->sem))
                         break;
@@ -591,7 +586,7 @@ static int dvb_frontend_thread(void *data)
                         fe->ops.sleep(fe);
         }
 
-        fepriv->thread_pid = 0;
+        fepriv->thread = NULL;
         mb();
 
         dvb_frontend_wakeup(fe);
@@ -600,7 +595,6 @@ static int dvb_frontend_thread(void *data)
 
 static void dvb_frontend_stop(struct dvb_frontend *fe)
 {
-        unsigned long ret;
         struct dvb_frontend_private *fepriv = fe->frontend_priv;
 
         dprintk ("%s\n", __FUNCTION__);
@@ -608,33 +602,17 @@ static void dvb_frontend_stop(struct dvb_frontend *fe)
         fepriv->exit = 1;
         mb();
 
-        if (!fepriv->thread_pid)
+        if (!fepriv->thread)
                 return;
 
-        /* check if the thread is really alive */
-        if (kill_proc(fepriv->thread_pid, 0, 1) == -ESRCH) {
-                printk("dvb_frontend_stop: thread PID %d already died\n",
-                                fepriv->thread_pid);
-                /* make sure the mutex was not held by the thread */
-                init_MUTEX (&fepriv->sem);
-                return;
-        }
-
-        /* wake up the frontend thread, so it notices that fe->exit == 1 */
-        dvb_frontend_wakeup(fe);
-
-        /* wait until the frontend thread has exited */
-        ret = wait_event_interruptible(fepriv->wait_queue,0 == fepriv->thread_pid);
-        if (-ERESTARTSYS != ret) {
-                fepriv->state = FESTATE_IDLE;
-                return;
-        }
+        kthread_stop(fepriv->thread);
+        init_MUTEX (&fepriv->sem);
         fepriv->state = FESTATE_IDLE;
 
         /* paranoia check in case a signal arrived */
-        if (fepriv->thread_pid)
-                printk("dvb_frontend_stop: warning: thread PID %d won't exit\n",
-                                fepriv->thread_pid);
+        if (fepriv->thread)
+                printk("dvb_frontend_stop: warning: thread %p won't exit\n",
+                                fepriv->thread);
 }
 
 s32 timeval_usec_diff(struct timeval lasttime, struct timeval curtime)
@@ -684,10 +662,11 @@ static int dvb_frontend_start(struct dvb_frontend *fe)
 {
         int ret;
         struct dvb_frontend_private *fepriv = fe->frontend_priv;
+        struct task_struct *fe_thread;
 
         dprintk ("%s\n", __FUNCTION__);
 
-        if (fepriv->thread_pid) {
+        if (fepriv->thread) {
                 if (!fepriv->exit)
                         return 0;
                 else
@@ -701,18 +680,18 @@ static int dvb_frontend_start(struct dvb_frontend *fe)
 
         fepriv->state = FESTATE_IDLE;
         fepriv->exit = 0;
-        fepriv->thread_pid = 0;
+        fepriv->thread = NULL;
         mb();
 
-        ret = kernel_thread (dvb_frontend_thread, fe, 0);
-
-        if (ret < 0) {
-                printk("dvb_frontend_start: failed to start kernel_thread (%d)\n", ret);
+        fe_thread = kthread_run(dvb_frontend_thread, fe,
+                "kdvb-fe-%i", fe->dvb->num);
+        if (IS_ERR(fe_thread)) {
+                ret = PTR_ERR(fe_thread);
+                printk("dvb_frontend_start: failed to start kthread (%d)\n", ret);
                 up(&fepriv->sem);
                 return ret;
         }
-        fepriv->thread_pid = ret;
-
+        fepriv->thread = fe_thread;
         return 0;
 }
 
diff --git a/drivers/media/dvb/ttpci/av7110.c b/drivers/media/dvb/ttpci/av7110.c
index bb213d836c90..29ed532ba966 100644
--- a/drivers/media/dvb/ttpci/av7110.c
+++ b/drivers/media/dvb/ttpci/av7110.c
@@ -51,6 +51,7 @@
 #include <linux/firmware.h>
 #include <linux/crc32.h>
 #include <linux/i2c.h>
+#include <linux/kthread.h>
 
 #include <asm/system.h>
 
@@ -223,11 +224,10 @@ static void recover_arm(struct av7110 *av7110)
 
 static void av7110_arm_sync(struct av7110 *av7110)
 {
-        av7110->arm_rmmod = 1;
-        wake_up_interruptible(&av7110->arm_wait);
+        if (av7110->arm_thread)
+                kthread_stop(av7110->arm_thread);
 
-        while (av7110->arm_thread)
-                msleep(1);
+        av7110->arm_thread = NULL;
 }
 
 static int arm_thread(void *data)
@@ -238,17 +238,11 @@ static int arm_thread(void *data)
 
         dprintk(4, "%p\n",av7110);
 
-        lock_kernel();
-        daemonize("arm_mon");
-        sigfillset(&current->blocked);
-        unlock_kernel();
-
-        av7110->arm_thread = current;
-
         for (;;) {
                 timeout = wait_event_interruptible_timeout(av7110->arm_wait,
-                                                           av7110->arm_rmmod, 5 * HZ);
-                if (-ERESTARTSYS == timeout || av7110->arm_rmmod) {
+                        kthread_should_stop(), 5 * HZ);
+
+                if (-ERESTARTSYS == timeout || kthread_should_stop()) {
                         /* got signal or told to quit*/
                         break;
                 }
@@ -276,7 +270,6 @@ static int arm_thread(void *data)
                 av7110->arm_errors = 0;
         }
 
-        av7110->arm_thread = NULL;
         return 0;
 }
 
@@ -2338,6 +2331,7 @@ static int __devinit av7110_attach(struct saa7146_dev* dev,
         const int length = TS_WIDTH * TS_HEIGHT;
         struct pci_dev *pdev = dev->pci;
         struct av7110 *av7110;
+        struct task_struct *thread;
         int ret, count = 0;
 
         dprintk(4, "dev: %p\n", dev);
@@ -2622,9 +2616,12 @@ static int __devinit av7110_attach(struct saa7146_dev* dev,
                 printk ("dvb-ttpci: Warning, firmware version 0x%04x is too old. "
                         "System might be unstable!\n", FW_VERSION(av7110->arm_app));
 
-        ret = kernel_thread(arm_thread, (void *) av7110, 0);
-        if (ret < 0)
+        thread = kthread_run(arm_thread, (void *) av7110, "arm_mon");
+        if (IS_ERR(thread)) {
+                ret = PTR_ERR(thread);
                 goto err_stop_arm_9;
+        }
+        av7110->arm_thread = thread;
 
         /* set initial volume in mixer struct */
         av7110->mixer.volume_left  = volume;
diff --git a/drivers/media/dvb/ttpci/av7110.h b/drivers/media/dvb/ttpci/av7110.h
index 1d05166bd853..b98bd453cade 100644
--- a/drivers/media/dvb/ttpci/av7110.h
+++ b/drivers/media/dvb/ttpci/av7110.h
@@ -204,7 +204,6 @@ struct av7110 {
         struct task_struct *arm_thread;
         wait_queue_head_t   arm_wait;
         u16                 arm_loops;
-        int                 arm_rmmod;
 
         void               *debi_virt;
         dma_addr_t          debi_bus;