tifm_7xx1: switch from workqueue to kthread

As there's only one work item (media_switcher) to handle and it's effectively
serialized with itself, I found it more convenient to use kthread instead of
workqueue. This also allows for a working implementation of suspend/resume,
which were totally broken in the past version.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>

diff --git a/drivers/misc/tifm_7xx1.c b/drivers/misc/tifm_7xx1.c
index 5ab81dd..d3e8ff4 100644 (file)
--- a/drivers/misc/tifm_7xx1.c
+++ b/drivers/misc/tifm_7xx1.c
@@ -11,6 +11,7 @@
 
 #include <linux/tifm.h>
 #include <linux/dma-mapping.h>
+#include <linux/freezer.h>
 
 #define DRIVER_NAME "tifm_7xx1"
 #define DRIVER_VERSION "0.7"
@@ -20,10 +21,8 @@ static void tifm_7xx1_eject(struct tifm_adapter *fm, struct tifm_dev *sock)
        unsigned long flags;
 
        spin_lock_irqsave(&fm->lock, flags);
-       if (!fm->inhibit_new_cards) {
-               fm->socket_change_set |= 1 << sock->socket_id;
-               queue_work(fm->wq, &fm->media_switcher);
-       }
+       fm->socket_change_set |= 1 << sock->socket_id;
+       wake_up_all(&fm->change_set_notify);
        spin_unlock_irqrestore(&fm->lock, flags);
 }
 
@@ -59,14 +58,10 @@ static irqreturn_t tifm_7xx1_isr(int irq, void *dev_id)
        }
        writel(irq_status, fm->addr + FM_INTERRUPT_STATUS);
 
-       if (!fm->inhibit_new_cards) {
-               if (!fm->socket_change_set) {
-                       writel(TIFM_IRQ_ENABLE,
-                               fm->addr + FM_SET_INTERRUPT_ENABLE);
-               } else {
-                       queue_work(fm->wq, &fm->media_switcher);
-               }
-       }
+       if (!fm->socket_change_set)
+               writel(TIFM_IRQ_ENABLE, fm->addr + FM_SET_INTERRUPT_ENABLE);
+       else
+               wake_up_all(&fm->change_set_notify);
 
        spin_unlock(&fm->lock);
        return IRQ_HANDLED;
@@ -123,21 +118,22 @@ tifm_7xx1_sock_addr(char __iomem *base_addr, unsigned int sock_num)
        return base_addr + ((sock_num + 1) << 10);
 }
 
-static void tifm_7xx1_switch_media(struct work_struct *work)
+static int tifm_7xx1_switch_media(void *data)
 {
-       struct tifm_adapter *fm =
-               container_of(work, struct tifm_adapter, media_switcher);
+       struct tifm_adapter *fm = data;
        unsigned long flags;
        tifm_media_id media_id;
        char *card_name = "xx";
-       int cnt;
+       int cnt, rc;
        struct tifm_dev *sock;
        unsigned int socket_change_set;
 
-       if (!class_device_get(&fm->cdev))
-               return;
-
        while (1) {
+               rc = wait_event_interruptible(fm->change_set_notify,
+                                             fm->socket_change_set);
+               if (rc == -ERESTARTSYS)
+                       try_to_freeze();
+
                spin_lock_irqsave(&fm->lock, flags);
                socket_change_set = fm->socket_change_set;
                fm->socket_change_set = 0;
@@ -145,12 +141,12 @@ static void tifm_7xx1_switch_media(struct work_struct *work)
                dev_dbg(fm->dev, "checking media set %x\n",
                        socket_change_set);
 
-               if (fm->inhibit_new_cards)
+               if (kthread_should_stop())
                        socket_change_set = (1 << fm->num_sockets) - 1;
                spin_unlock_irqrestore(&fm->lock, flags);
 
                if (!socket_change_set)
-                       break;
+                       continue;
 
                spin_lock_irqsave(&fm->lock, flags);
                for (cnt = 0; cnt < fm->num_sockets; cnt++) {
@@ -169,7 +165,7 @@ static void tifm_7xx1_switch_media(struct work_struct *work)
                                       tifm_7xx1_sock_addr(fm->addr, cnt)
                                       + SOCK_CONTROL);
                        }
-                       if (fm->inhibit_new_cards)
+                       if (kthread_should_stop())
                                continue;
 
                        spin_unlock_irqrestore(&fm->lock, flags);
@@ -218,7 +214,7 @@ static void tifm_7xx1_switch_media(struct work_struct *work)
                        }
                }
 
-               if (!fm->inhibit_new_cards) {
+               if (!kthread_should_stop()) {
                        writel(TIFM_IRQ_FIFOMASK(socket_change_set)
                               | TIFM_IRQ_CARDMASK(socket_change_set),
                               fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
@@ -228,7 +224,6 @@ static void tifm_7xx1_switch_media(struct work_struct *work)
                        writel(TIFM_IRQ_ENABLE,
                               fm->addr + FM_SET_INTERRUPT_ENABLE);
                        spin_unlock_irqrestore(&fm->lock, flags);
-                       break;
                } else {
                        for (cnt = 0; cnt < fm->num_sockets; cnt++) {
                                if (fm->sockets[cnt])
@@ -236,56 +231,93 @@ static void tifm_7xx1_switch_media(struct work_struct *work)
                        }
                        if (!fm->socket_change_set) {
                                spin_unlock_irqrestore(&fm->lock, flags);
-                               break;
+                               return 0;
                        } else {
                                spin_unlock_irqrestore(&fm->lock, flags);
                        }
                }
        }
-       class_device_put(&fm->cdev);
+       return 0;
 }
 
+#ifdef CONFIG_PM
+
 static int tifm_7xx1_suspend(struct pci_dev *dev, pm_message_t state)
 {
-       struct tifm_adapter *fm = pci_get_drvdata(dev);
-       unsigned long flags;
+       dev_dbg(&dev->dev, "suspending host\n");
 
-       spin_lock_irqsave(&fm->lock, flags);
-       fm->inhibit_new_cards = 1;
-       fm->socket_change_set = 0xf;
-       writel(TIFM_IRQ_ENABLE, fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
-       spin_unlock_irqrestore(&fm->lock, flags);
-       flush_workqueue(fm->wq);
-
-       tifm_7xx1_switch_media(&fm->media_switcher);
-
-       pci_set_power_state(dev, PCI_D3hot);
-        pci_disable_device(dev);
-        pci_save_state(dev);
+       pci_save_state(dev);
+       pci_enable_wake(dev, pci_choose_state(dev, state), 0);
+       pci_disable_device(dev);
+       pci_set_power_state(dev, pci_choose_state(dev, state));
        return 0;
 }
 
 static int tifm_7xx1_resume(struct pci_dev *dev)
 {
        struct tifm_adapter *fm = pci_get_drvdata(dev);
+       int cnt, rc;
        unsigned long flags;
+       tifm_media_id new_ids[fm->num_sockets];
 
+       pci_set_power_state(dev, PCI_D0);
        pci_restore_state(dev);
-        pci_enable_device(dev);
-        pci_set_power_state(dev, PCI_D0);
-        pci_set_master(dev);
+       rc = pci_enable_device(dev);
+       if (rc)
+               return rc;
+       pci_set_master(dev);
+
+       dev_dbg(&dev->dev, "resuming host\n");
 
+       for (cnt = 0; cnt < fm->num_sockets; cnt++)
+               new_ids[cnt] = tifm_7xx1_toggle_sock_power(
+                                       tifm_7xx1_sock_addr(fm->addr, cnt),
+                                       fm->num_sockets == 2);
        spin_lock_irqsave(&fm->lock, flags);
-       fm->inhibit_new_cards = 0;
-       writel(TIFM_IRQ_SETALL, fm->addr + FM_INTERRUPT_STATUS);
-       writel(TIFM_IRQ_SETALL, fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
+       fm->socket_change_set = 0;
+       for (cnt = 0; cnt < fm->num_sockets; cnt++) {
+               if (fm->sockets[cnt]) {
+                       if (fm->sockets[cnt]->media_id == new_ids[cnt])
+                               fm->socket_change_set |= 1 << cnt;
+
+                       fm->sockets[cnt]->media_id = new_ids[cnt];
+               }
+       }
+
        writel(TIFM_IRQ_ENABLE | TIFM_IRQ_SOCKMASK((1 << fm->num_sockets) - 1),
-               fm->addr + FM_SET_INTERRUPT_ENABLE);
-       fm->socket_change_set = 0xf;
+              fm->addr + FM_SET_INTERRUPT_ENABLE);
+       if (!fm->socket_change_set) {
+               spin_unlock_irqrestore(&fm->lock, flags);
+               return 0;
+       } else {
+               fm->socket_change_set = 0;
+               spin_unlock_irqrestore(&fm->lock, flags);
+       }
+
+       wait_event_timeout(fm->change_set_notify, fm->socket_change_set, HZ);
+
+       spin_lock_irqsave(&fm->lock, flags);
+       writel(TIFM_IRQ_FIFOMASK(fm->socket_change_set)
+              | TIFM_IRQ_CARDMASK(fm->socket_change_set),
+              fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
+       writel(TIFM_IRQ_FIFOMASK(fm->socket_change_set)
+              | TIFM_IRQ_CARDMASK(fm->socket_change_set),
+              fm->addr + FM_SET_INTERRUPT_ENABLE);
+       writel(TIFM_IRQ_ENABLE,
+              fm->addr + FM_SET_INTERRUPT_ENABLE);
+       fm->socket_change_set = 0;
+
        spin_unlock_irqrestore(&fm->lock, flags);
        return 0;
 }
 
+#else
+
+#define tifm_7xx1_suspend NULL
+#define tifm_7xx1_resume NULL
+
+#endif /* CONFIG_PM */
+
 static int tifm_7xx1_probe(struct pci_dev *dev,
                        const struct pci_device_id *dev_id)
 {
@@ -324,7 +356,6 @@ static int tifm_7xx1_probe(struct pci_dev *dev,
        if (!fm->sockets)
                goto err_out_free;
 
-       INIT_WORK(&fm->media_switcher, tifm_7xx1_switch_media);
        fm->eject = tifm_7xx1_eject;
        pci_set_drvdata(dev, fm);
 
@@ -337,16 +368,15 @@ static int tifm_7xx1_probe(struct pci_dev *dev,
        if (rc)
                goto err_out_unmap;
 
-       rc = tifm_add_adapter(fm);
+       init_waitqueue_head(&fm->change_set_notify);
+       rc = tifm_add_adapter(fm, tifm_7xx1_switch_media);
        if (rc)
                goto err_out_irq;
 
        writel(TIFM_IRQ_SETALL, fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
        writel(TIFM_IRQ_ENABLE | TIFM_IRQ_SOCKMASK((1 << fm->num_sockets) - 1),
                fm->addr + FM_SET_INTERRUPT_ENABLE);
-
-       fm->socket_change_set = 0xf;
-
+       wake_up_process(fm->media_switcher);
        return 0;
 
 err_out_irq:
@@ -370,18 +400,15 @@ static void tifm_7xx1_remove(struct pci_dev *dev)
        struct tifm_adapter *fm = pci_get_drvdata(dev);
        unsigned long flags;
 
+       writel(TIFM_IRQ_SETALL, fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
+       mmiowb();
+       free_irq(dev->irq, fm);
+
        spin_lock_irqsave(&fm->lock, flags);
-       fm->inhibit_new_cards = 1;
-       fm->socket_change_set = 0xf;
-       writel(TIFM_IRQ_ENABLE, fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
+       fm->socket_change_set = (1 << fm->num_sockets) - 1;
        spin_unlock_irqrestore(&fm->lock, flags);
 
-       flush_workqueue(fm->wq);
-
-       tifm_7xx1_switch_media(&fm->media_switcher);
-
-       writel(TIFM_IRQ_SETALL, fm->addr + FM_CLEAR_INTERRUPT_ENABLE);
-       free_irq(dev->irq, fm);
+       kthread_stop(fm->media_switcher);
 
        tifm_remove_adapter(fm);
 

diff --git a/drivers/misc/tifm_core.c b/drivers/misc/tifm_core.c
index 3eaf2c9..4d62dab 100644 (file)
--- a/drivers/misc/tifm_core.c
+++ b/drivers/misc/tifm_core.c
@@ -71,8 +71,6 @@ static void tifm_free(struct class_device *cdev)
        struct tifm_adapter *fm = container_of(cdev, struct tifm_adapter, cdev);
 
        kfree(fm->sockets);
-       if (fm->wq)
-               destroy_workqueue(fm->wq);
        kfree(fm);
 }
 
@@ -101,7 +99,8 @@ void tifm_free_adapter(struct tifm_adapter *fm)
 }
 EXPORT_SYMBOL(tifm_free_adapter);
 
-int tifm_add_adapter(struct tifm_adapter *fm)
+int tifm_add_adapter(struct tifm_adapter *fm,
+                    int (*mediathreadfn)(void *data))
 {
        int rc;
 
@@ -113,10 +112,10 @@ int tifm_add_adapter(struct tifm_adapter *fm)
        spin_unlock(&tifm_adapter_lock);
        if (!rc) {
                snprintf(fm->cdev.class_id, BUS_ID_SIZE, "tifm%u", fm->id);
-               strncpy(fm->wq_name, fm->cdev.class_id, KOBJ_NAME_LEN);
+               fm->media_switcher = kthread_create(mediathreadfn,
+                                                   fm, "tifm/%u", fm->id);
 
-               fm->wq = create_singlethread_workqueue(fm->wq_name);
-               if (fm->wq)
+               if (!IS_ERR(fm->media_switcher))
                        return class_device_add(&fm->cdev);
 
                spin_lock(&tifm_adapter_lock);

diff --git a/include/linux/tifm.h b/include/linux/tifm.h
index eaf9e1f..e5a8295 100644 (file)
--- a/include/linux/tifm.h
+++ b/include/linux/tifm.h
@@ -17,7 +17,7 @@
 #include <linux/wait.h>
 #include <linux/delay.h>
 #include <linux/pci.h>
-#include <linux/scatterlist.h>
+#include <linux/kthread.h>
 
 /* Host registers (relative to pci base address): */
 enum {
@@ -110,13 +110,11 @@ struct tifm_adapter {
        spinlock_t              lock;
        unsigned int            irq_status;
        unsigned int            socket_change_set;
+       wait_queue_head_t       change_set_notify;
        unsigned int            id;
        unsigned int            num_sockets;
        struct tifm_dev         **sockets;
-       char                    wq_name[KOBJ_NAME_LEN];
-       unsigned int            inhibit_new_cards;
-       struct workqueue_struct *wq;
-       struct work_struct      media_switcher;
+       struct task_struct      *media_switcher;
        struct class_device     cdev;
        struct device           *dev;
 
@@ -126,7 +124,7 @@ struct tifm_adapter {
 struct tifm_adapter *tifm_alloc_adapter(void);
 void tifm_free_device(struct device *dev);
 void tifm_free_adapter(struct tifm_adapter *fm);
-int tifm_add_adapter(struct tifm_adapter *fm);
+int tifm_add_adapter(struct tifm_adapter *fm, int (*mediathreadfn)(void *data));
 void tifm_remove_adapter(struct tifm_adapter *fm);
 struct tifm_dev *tifm_alloc_device(struct tifm_adapter *fm);
 int tifm_register_driver(struct tifm_driver *drv);