memstick: use fully asynchronous request processing
Alex Dubov [Sat, 26 Jul 2008 02:45:02 +0000 (19:45 -0700)]
Instead of using a separate thread to pump requests from block layer queue
to memstick, do so inline, utilizing the callback design of the memstick.

[akpm@linux-foundation.org: fix warnings]
Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/memstick/core/memstick.c
drivers/memstick/core/mspro_block.c
drivers/memstick/host/jmb38x_ms.c
drivers/memstick/host/tifm_ms.c

index 7162f77..a380050 100644 (file)
@@ -249,8 +249,11 @@ EXPORT_SYMBOL(memstick_next_req);
  */
 void memstick_new_req(struct memstick_host *host)
 {
-       host->retries = cmd_retries;
-       host->request(host);
+       if (host->card) {
+               host->retries = cmd_retries;
+               INIT_COMPLETION(host->card->mrq_complete);
+               host->request(host);
+       }
 }
 EXPORT_SYMBOL(memstick_new_req);
 
index 004ac4d..44b1817 100644 (file)
@@ -136,9 +136,8 @@ struct mspro_block_data {
        unsigned int          caps;
        struct gendisk        *disk;
        struct request_queue  *queue;
+       struct request        *block_req;
        spinlock_t            q_lock;
-       wait_queue_head_t     q_wait;
-       struct task_struct    *q_thread;
 
        unsigned short        page_size;
        unsigned short        cylinders;
@@ -147,9 +146,10 @@ struct mspro_block_data {
 
        unsigned char         system;
        unsigned char         read_only:1,
-                             active:1,
+                             eject:1,
                              has_request:1,
-                             data_dir:1;
+                             data_dir:1,
+                             active:1;
        unsigned char         transfer_cmd;
 
        int                   (*mrq_handler)(struct memstick_dev *card,
@@ -160,12 +160,14 @@ struct mspro_block_data {
        struct scatterlist    req_sg[MSPRO_BLOCK_MAX_SEGS];
        unsigned int          seg_count;
        unsigned int          current_seg;
-       unsigned short        current_page;
+       unsigned int          current_page;
 };
 
 static DEFINE_IDR(mspro_block_disk_idr);
 static DEFINE_MUTEX(mspro_block_disk_lock);
 
+static int mspro_block_complete_req(struct memstick_dev *card, int error);
+
 /*** Block device ***/
 
 static int mspro_block_bd_open(struct inode *inode, struct file *filp)
@@ -197,8 +199,10 @@ static int mspro_block_disk_release(struct gendisk *disk)
 
        mutex_lock(&mspro_block_disk_lock);
 
-       if (msb->usage_count) {
-               msb->usage_count--;
+       if (msb) {
+               if (msb->usage_count)
+                       msb->usage_count--;
+
                if (!msb->usage_count) {
                        kfree(msb);
                        disk->private_data = NULL;
@@ -523,11 +527,13 @@ static int h_mspro_block_req_init(struct memstick_dev *card,
 static int h_mspro_block_default(struct memstick_dev *card,
                                 struct memstick_request **mrq)
 {
-       complete(&card->mrq_complete);
-       if (!(*mrq)->error)
-               return -EAGAIN;
-       else
-               return (*mrq)->error;
+       return mspro_block_complete_req(card, (*mrq)->error);
+}
+
+static int h_mspro_block_default_bad(struct memstick_dev *card,
+                                    struct memstick_request **mrq)
+{
+       return -ENXIO;
 }
 
 static int h_mspro_block_get_ro(struct memstick_dev *card,
@@ -535,44 +541,30 @@ static int h_mspro_block_get_ro(struct memstick_dev *card,
 {
        struct mspro_block_data *msb = memstick_get_drvdata(card);
 
-       if ((*mrq)->error) {
-               complete(&card->mrq_complete);
-               return (*mrq)->error;
+       if (!(*mrq)->error) {
+               if ((*mrq)->data[offsetof(struct ms_status_register, status0)]
+                   & MEMSTICK_STATUS0_WP)
+                       msb->read_only = 1;
+               else
+                       msb->read_only = 0;
        }
 
-       if ((*mrq)->data[offsetof(struct ms_status_register, status0)]
-           & MEMSTICK_STATUS0_WP)
-               msb->read_only = 1;
-       else
-               msb->read_only = 0;
-
-       complete(&card->mrq_complete);
-       return -EAGAIN;
+       return mspro_block_complete_req(card, (*mrq)->error);
 }
 
 static int h_mspro_block_wait_for_ced(struct memstick_dev *card,
                                      struct memstick_request **mrq)
 {
-       if ((*mrq)->error) {
-               complete(&card->mrq_complete);
-               return (*mrq)->error;
-       }
-
        dev_dbg(&card->dev, "wait for ced: value %x\n", (*mrq)->data[0]);
 
-       if ((*mrq)->data[0] & (MEMSTICK_INT_CMDNAK | MEMSTICK_INT_ERR)) {
-               card->current_mrq.error = -EFAULT;
-               complete(&card->mrq_complete);
-               return card->current_mrq.error;
+       if (!(*mrq)->error) {
+               if ((*mrq)->data[0] & (MEMSTICK_INT_CMDNAK | MEMSTICK_INT_ERR))
+                       (*mrq)->error = -EFAULT;
+               else if (!((*mrq)->data[0] & MEMSTICK_INT_CED))
+                       return 0;
        }
 
-       if (!((*mrq)->data[0] & MEMSTICK_INT_CED))
-               return 0;
-       else {
-               card->current_mrq.error = 0;
-               complete(&card->mrq_complete);
-               return -EAGAIN;
-       }
+       return mspro_block_complete_req(card, (*mrq)->error);
 }
 
 static int h_mspro_block_transfer_data(struct memstick_dev *card,
@@ -583,10 +575,8 @@ static int h_mspro_block_transfer_data(struct memstick_dev *card,
        struct scatterlist t_sg = { 0 };
        size_t t_offset;
 
-       if ((*mrq)->error) {
-               complete(&card->mrq_complete);
-               return (*mrq)->error;
-       }
+       if ((*mrq)->error)
+               return mspro_block_complete_req(card, (*mrq)->error);
 
        switch ((*mrq)->tpc) {
        case MS_TPC_WRITE_REG:
@@ -617,8 +607,8 @@ has_int_reg:
 
                        if (msb->current_seg == msb->seg_count) {
                                if (t_val & MEMSTICK_INT_CED) {
-                                       complete(&card->mrq_complete);
-                                       return -EAGAIN;
+                                       return mspro_block_complete_req(card,
+                                                                       0);
                                } else {
                                        card->next_request
                                                = h_mspro_block_wait_for_ced;
@@ -666,90 +656,120 @@ has_int_reg:
 
 /*** Data transfer ***/
 
-static void mspro_block_process_request(struct memstick_dev *card,
-                                       struct request *req)
+static int mspro_block_issue_req(struct memstick_dev *card, int chunk)
 {
        struct mspro_block_data *msb = memstick_get_drvdata(card);
-       struct mspro_param_register param;
-       int rc, chunk, cnt;
-       unsigned short page_count;
        sector_t t_sec;
-       unsigned long flags;
+       unsigned int count;
+       struct mspro_param_register param;
 
-       do {
-               page_count = 0;
+try_again:
+       while (chunk) {
+               msb->current_page = 0;
                msb->current_seg = 0;
-               msb->seg_count = blk_rq_map_sg(req->q, req, msb->req_sg);
+               msb->seg_count = blk_rq_map_sg(msb->block_req->q,
+                                              msb->block_req,
+                                              msb->req_sg);
 
-               if (msb->seg_count) {
-                       msb->current_page = 0;
-                       for (rc = 0; rc < msb->seg_count; rc++)
-                               page_count += msb->req_sg[rc].length
-                                             / msb->page_size;
-
-                       t_sec = req->sector;
-                       sector_div(t_sec, msb->page_size >> 9);
-                       param.system = msb->system;
-                       param.data_count = cpu_to_be16(page_count);
-                       param.data_address = cpu_to_be32((uint32_t)t_sec);
-                       param.tpc_param = 0;
-
-                       msb->data_dir = rq_data_dir(req);
-                       msb->transfer_cmd = msb->data_dir == READ
-                                           ? MSPRO_CMD_READ_DATA
-                                           : MSPRO_CMD_WRITE_DATA;
-
-                       dev_dbg(&card->dev, "data transfer: cmd %x, "
-                               "lba %x, count %x\n", msb->transfer_cmd,
-                               be32_to_cpu(param.data_address),
-                               page_count);
-
-                       card->next_request = h_mspro_block_req_init;
-                       msb->mrq_handler = h_mspro_block_transfer_data;
-                       memstick_init_req(&card->current_mrq, MS_TPC_WRITE_REG,
-                                         &param, sizeof(param));
-                       memstick_new_req(card->host);
-                       wait_for_completion(&card->mrq_complete);
-                       rc = card->current_mrq.error;
+               if (!msb->seg_count) {
+                       chunk = __blk_end_request(msb->block_req, -ENOMEM,
+                                       blk_rq_cur_bytes(msb->block_req));
+                       continue;
+               }
 
-                       if (rc || (card->current_mrq.tpc == MSPRO_CMD_STOP)) {
-                               for (cnt = 0; cnt < msb->current_seg; cnt++)
-                                       page_count += msb->req_sg[cnt].length
-                                                     / msb->page_size;
-
-                               if (msb->current_page)
-                                       page_count += msb->current_page - 1;
-
-                               if (page_count && (msb->data_dir == READ))
-                                       rc = msb->page_size * page_count;
-                               else
-                                       rc = -EIO;
-                       } else
-                               rc = msb->page_size * page_count;
-               } else
-                       rc = -EFAULT;
+               t_sec = msb->block_req->sector << 9;
+               sector_div(t_sec, msb->page_size);
 
-               spin_lock_irqsave(&msb->q_lock, flags);
-               if (rc >= 0)
-                       chunk = __blk_end_request(req, 0, rc);
-               else
-                       chunk = __blk_end_request(req, rc, 0);
+               count = msb->block_req->nr_sectors << 9;
+               count /= msb->page_size;
 
-               dev_dbg(&card->dev, "end chunk %d, %d\n", rc, chunk);
-               spin_unlock_irqrestore(&msb->q_lock, flags);
-       } while (chunk);
+               param.system = msb->system;
+               param.data_count = cpu_to_be16(count);
+               param.data_address = cpu_to_be32((uint32_t)t_sec);
+               param.tpc_param = 0;
+
+               msb->data_dir = rq_data_dir(msb->block_req);
+               msb->transfer_cmd = msb->data_dir == READ
+                                   ? MSPRO_CMD_READ_DATA
+                                   : MSPRO_CMD_WRITE_DATA;
+
+               dev_dbg(&card->dev, "data transfer: cmd %x, "
+                       "lba %x, count %x\n", msb->transfer_cmd,
+                       be32_to_cpu(param.data_address), count);
+
+               card->next_request = h_mspro_block_req_init;
+               msb->mrq_handler = h_mspro_block_transfer_data;
+               memstick_init_req(&card->current_mrq, MS_TPC_WRITE_REG,
+                                 &param, sizeof(param));
+               memstick_new_req(card->host);
+               return 0;
+       }
+
+       dev_dbg(&card->dev, "elv_next\n");
+       msb->block_req = elv_next_request(msb->queue);
+       if (!msb->block_req) {
+               dev_dbg(&card->dev, "issue end\n");
+               return -EAGAIN;
+       }
+
+       dev_dbg(&card->dev, "trying again\n");
+       chunk = 1;
+       goto try_again;
 }
 
-static int mspro_block_has_request(struct mspro_block_data *msb)
+static int mspro_block_complete_req(struct memstick_dev *card, int error)
 {
-       int rc = 0;
+       struct mspro_block_data *msb = memstick_get_drvdata(card);
+       int chunk, cnt;
+       unsigned int t_len = 0;
        unsigned long flags;
 
        spin_lock_irqsave(&msb->q_lock, flags);
-       if (kthread_should_stop() || msb->has_request)
-               rc = 1;
+       dev_dbg(&card->dev, "complete %d, %d\n", msb->has_request ? 1 : 0,
+               error);
+
+       if (msb->has_request) {
+               /* Nothing to do - not really an error */
+               if (error == -EAGAIN)
+                       error = 0;
+
+               if (error || (card->current_mrq.tpc == MSPRO_CMD_STOP)) {
+                       if (msb->data_dir == READ) {
+                               for (cnt = 0; cnt < msb->current_seg; cnt++)
+                                       t_len += msb->req_sg[cnt].length
+                                                / msb->page_size;
+
+                                       if (msb->current_page)
+                                               t_len += msb->current_page - 1;
+
+                                       t_len *= msb->page_size;
+                       }
+               } else
+                       t_len = msb->block_req->nr_sectors << 9;
+
+               dev_dbg(&card->dev, "transferred %x (%d)\n", t_len, error);
+
+               if (error && !t_len)
+                       t_len = blk_rq_cur_bytes(msb->block_req);
+
+               chunk = __blk_end_request(msb->block_req, error, t_len);
+
+               error = mspro_block_issue_req(card, chunk);
+
+               if (!error)
+                       goto out;
+               else
+                       msb->has_request = 0;
+       } else {
+               if (!error)
+                       error = -EAGAIN;
+       }
+
+       card->next_request = h_mspro_block_default_bad;
+       complete_all(&card->mrq_complete);
+out:
        spin_unlock_irqrestore(&msb->q_lock, flags);
-       return rc;
+       return error;
 }
 
 static void mspro_block_stop(struct memstick_dev *card)
@@ -783,54 +803,37 @@ static void mspro_block_start(struct memstick_dev *card)
        spin_unlock_irqrestore(&msb->q_lock, flags);
 }
 
-static int mspro_block_queue_thread(void *data)
+static int mspro_block_prepare_req(struct request_queue *q, struct request *req)
 {
-       struct memstick_dev *card = data;
-       struct memstick_host *host = card->host;
-       struct mspro_block_data *msb = memstick_get_drvdata(card);
-       struct request *req;
-       unsigned long flags;
-
-       while (1) {
-               wait_event(msb->q_wait, mspro_block_has_request(msb));
-               dev_dbg(&card->dev, "thread iter\n");
+       if (!blk_fs_request(req) && !blk_pc_request(req)) {
+               blk_dump_rq_flags(req, "MSPro unsupported request");
+               return BLKPREP_KILL;
+       }
 
-               spin_lock_irqsave(&msb->q_lock, flags);
-               req = elv_next_request(msb->queue);
-               dev_dbg(&card->dev, "next req %p\n", req);
-               if (!req) {
-                       msb->has_request = 0;
-                       if (kthread_should_stop()) {
-                               spin_unlock_irqrestore(&msb->q_lock, flags);
-                               break;
-                       }
-               } else
-                       msb->has_request = 1;
-               spin_unlock_irqrestore(&msb->q_lock, flags);
+       req->cmd_flags |= REQ_DONTPREP;
 
-               if (req) {
-                       mutex_lock(&host->lock);
-                       mspro_block_process_request(card, req);
-                       mutex_unlock(&host->lock);
-               }
-       }
-       dev_dbg(&card->dev, "thread finished\n");
-       return 0;
+       return BLKPREP_OK;
 }
 
-static void mspro_block_request(struct request_queue *q)
+static void mspro_block_submit_req(struct request_queue *q)
 {
        struct memstick_dev *card = q->queuedata;
        struct mspro_block_data *msb = memstick_get_drvdata(card);
        struct request *req = NULL;
 
-       if (msb->q_thread) {
-               msb->has_request = 1;
-               wake_up_all(&msb->q_wait);
-       } else {
+       if (msb->has_request)
+               return;
+
+       if (msb->eject) {
                while ((req = elv_next_request(q)) != NULL)
                        end_queued_request(req, -ENODEV);
+
+               return;
        }
+
+       msb->has_request = 1;
+       if (mspro_block_issue_req(card, 0))
+               msb->has_request = 0;
 }
 
 /*** Initialization ***/
@@ -1200,16 +1203,14 @@ static int mspro_block_init_disk(struct memstick_dev *card)
                goto out_release_id;
        }
 
-       spin_lock_init(&msb->q_lock);
-       init_waitqueue_head(&msb->q_wait);
-
-       msb->queue = blk_init_queue(mspro_block_request, &msb->q_lock);
+       msb->queue = blk_init_queue(mspro_block_submit_req, &msb->q_lock);
        if (!msb->queue) {
                rc = -ENOMEM;
                goto out_put_disk;
        }
 
        msb->queue->queuedata = card;
+       blk_queue_prep_rq(msb->queue, mspro_block_prepare_req);
 
        blk_queue_bounce_limit(msb->queue, limit);
        blk_queue_max_sectors(msb->queue, MSPRO_BLOCK_MAX_PAGES);
@@ -1235,14 +1236,8 @@ static int mspro_block_init_disk(struct memstick_dev *card)
        capacity *= msb->page_size >> 9;
        set_capacity(msb->disk, capacity);
        dev_dbg(&card->dev, "capacity set %ld\n", capacity);
-       msb->q_thread = kthread_run(mspro_block_queue_thread, card,
-                                   DRIVER_NAME"d");
-       if (IS_ERR(msb->q_thread))
-               goto out_put_disk;
 
-       mutex_unlock(&host->lock);
        add_disk(msb->disk);
-       mutex_lock(&host->lock);
        msb->active = 1;
        return 0;
 
@@ -1290,6 +1285,7 @@ static int mspro_block_probe(struct memstick_dev *card)
                return -ENOMEM;
        memstick_set_drvdata(card, msb);
        msb->card = card;
+       spin_lock_init(&msb->q_lock);
 
        rc = mspro_block_init_card(card);
 
@@ -1319,26 +1315,17 @@ out_free:
 static void mspro_block_remove(struct memstick_dev *card)
 {
        struct mspro_block_data *msb = memstick_get_drvdata(card);
-       struct task_struct *q_thread = NULL;
        unsigned long flags;
 
        del_gendisk(msb->disk);
        dev_dbg(&card->dev, "mspro block remove\n");
        spin_lock_irqsave(&msb->q_lock, flags);
-       q_thread = msb->q_thread;
-       msb->q_thread = NULL;
-       msb->active = 0;
+       msb->eject = 1;
+       blk_start_queue(msb->queue);
        spin_unlock_irqrestore(&msb->q_lock, flags);
 
-       if (q_thread) {
-               mutex_unlock(&card->host->lock);
-               kthread_stop(q_thread);
-               mutex_lock(&card->host->lock);
-       }
-
-       dev_dbg(&card->dev, "queue thread stopped\n");
-
        blk_cleanup_queue(msb->queue);
+       msb->queue = NULL;
 
        sysfs_remove_group(&card->dev.kobj, &msb->attr_group);
 
@@ -1355,19 +1342,13 @@ static void mspro_block_remove(struct memstick_dev *card)
 static int mspro_block_suspend(struct memstick_dev *card, pm_message_t state)
 {
        struct mspro_block_data *msb = memstick_get_drvdata(card);
-       struct task_struct *q_thread = NULL;
        unsigned long flags;
 
        spin_lock_irqsave(&msb->q_lock, flags);
-       q_thread = msb->q_thread;
-       msb->q_thread = NULL;
-       msb->active = 0;
        blk_stop_queue(msb->queue);
+       msb->active = 0;
        spin_unlock_irqrestore(&msb->q_lock, flags);
 
-       if (q_thread)
-               kthread_stop(q_thread);
-
        return 0;
 }
 
@@ -1406,14 +1387,7 @@ static int mspro_block_resume(struct memstick_dev *card)
                        if (memcmp(s_attr->data, r_attr->data, s_attr->size))
                                break;
 
-                       memstick_set_drvdata(card, msb);
-                       msb->q_thread = kthread_run(mspro_block_queue_thread,
-                                                   card, DRIVER_NAME"d");
-                       if (IS_ERR(msb->q_thread))
-                               msb->q_thread = NULL;
-                       else
-                               msb->active = 1;
-
+                       msb->active = 1;
                        break;
                }
        }
index 9d82e67..3485c63 100644 (file)
@@ -50,6 +50,7 @@ struct jmb38x_ms_host {
        struct jmb38x_ms        *chip;
        void __iomem            *addr;
        spinlock_t              lock;
+       struct tasklet_struct   notify;
        int                     id;
        char                    host_id[32];
        int                     irq;
@@ -590,25 +591,35 @@ static void jmb38x_ms_abort(unsigned long data)
        spin_unlock_irqrestore(&host->lock, flags);
 }
 
-static void jmb38x_ms_request(struct memstick_host *msh)
+static void jmb38x_ms_req_tasklet(unsigned long data)
 {
+       struct memstick_host *msh = (struct memstick_host *)data;
        struct jmb38x_ms_host *host = memstick_priv(msh);
        unsigned long flags;
        int rc;
 
        spin_lock_irqsave(&host->lock, flags);
-       if (host->req) {
-               spin_unlock_irqrestore(&host->lock, flags);
-               BUG();
-               return;
+       if (!host->req) {
+               do {
+                       rc = memstick_next_req(msh, &host->req);
+                       dev_dbg(&host->chip->pdev->dev, "tasklet req %d\n", rc);
+               } while (!rc && jmb38x_ms_issue_cmd(msh));
        }
-
-       do {
-               rc = memstick_next_req(msh, &host->req);
-       } while (!rc && jmb38x_ms_issue_cmd(msh));
        spin_unlock_irqrestore(&host->lock, flags);
 }
 
+static void jmb38x_ms_dummy_submit(struct memstick_host *msh)
+{
+       return;
+}
+
+static void jmb38x_ms_submit_req(struct memstick_host *msh)
+{
+       struct jmb38x_ms_host *host = memstick_priv(msh);
+
+       tasklet_schedule(&host->notify);
+}
+
 static int jmb38x_ms_reset(struct jmb38x_ms_host *host)
 {
        int cnt;
@@ -816,7 +827,9 @@ static struct memstick_host *jmb38x_ms_alloc_host(struct jmb38x_ms *jm, int cnt)
                 host->id);
        host->irq = jm->pdev->irq;
        host->timeout_jiffies = msecs_to_jiffies(1000);
-       msh->request = jmb38x_ms_request;
+
+       tasklet_init(&host->notify, jmb38x_ms_req_tasklet, (unsigned long)msh);
+       msh->request = jmb38x_ms_submit_req;
        msh->set_param = jmb38x_ms_set_param;
 
        msh->caps = MEMSTICK_CAP_PAR4 | MEMSTICK_CAP_PAR8;
@@ -928,6 +941,8 @@ static void jmb38x_ms_remove(struct pci_dev *dev)
 
                host = memstick_priv(jm->hosts[cnt]);
 
+               jm->hosts[cnt]->request = jmb38x_ms_dummy_submit;
+               tasklet_kill(&host->notify);
                writel(0, host->addr + INT_SIGNAL_ENABLE);
                writel(0, host->addr + INT_STATUS_ENABLE);
                mmiowb();
index 1445876..d32d6ad 100644 (file)
@@ -71,6 +71,7 @@ struct tifm_ms {
        struct tifm_dev         *dev;
        struct timer_list       timer;
        struct memstick_request *req;
+       struct tasklet_struct   notify;
        unsigned int            mode_mask;
        unsigned int            block_pos;
        unsigned long           timeout_jiffies;
@@ -455,40 +456,45 @@ static void tifm_ms_card_event(struct tifm_dev *sock)
        return;
 }
 
-static void tifm_ms_request(struct memstick_host *msh)
+static void tifm_ms_req_tasklet(unsigned long data)
 {
+       struct memstick_host *msh = (struct memstick_host *)data;
        struct tifm_ms *host = memstick_priv(msh);
        struct tifm_dev *sock = host->dev;
        unsigned long flags;
        int rc;
 
        spin_lock_irqsave(&sock->lock, flags);
-       if (host->req) {
-               printk(KERN_ERR "%s : unfinished request detected\n",
-                      sock->dev.bus_id);
-               spin_unlock_irqrestore(&sock->lock, flags);
-               tifm_eject(host->dev);
-               return;
-       }
+       if (!host->req) {
+               if (host->eject) {
+                       do {
+                               rc = memstick_next_req(msh, &host->req);
+                               if (!rc)
+                                       host->req->error = -ETIME;
+                       } while (!rc);
+                       spin_unlock_irqrestore(&sock->lock, flags);
+                       return;
+               }
 
-       if (host->eject) {
                do {
                        rc = memstick_next_req(msh, &host->req);
-                       if (!rc)
-                               host->req->error = -ETIME;
-               } while (!rc);
-               spin_unlock_irqrestore(&sock->lock, flags);
-               return;
+               } while (!rc && tifm_ms_issue_cmd(host));
        }
-
-       do {
-               rc = memstick_next_req(msh, &host->req);
-       } while (!rc && tifm_ms_issue_cmd(host));
-
        spin_unlock_irqrestore(&sock->lock, flags);
+}
+
+static void tifm_ms_dummy_submit(struct memstick_host *msh)
+{
        return;
 }
 
+static void tifm_ms_submit_req(struct memstick_host *msh)
+{
+       struct tifm_ms *host = memstick_priv(msh);
+
+       tasklet_schedule(&host->notify);
+}
+
 static int tifm_ms_set_param(struct memstick_host *msh,
                             enum memstick_param param,
                             int value)
@@ -569,8 +575,9 @@ static int tifm_ms_probe(struct tifm_dev *sock)
        host->timeout_jiffies = msecs_to_jiffies(1000);
 
        setup_timer(&host->timer, tifm_ms_abort, (unsigned long)host);
+       tasklet_init(&host->notify, tifm_ms_req_tasklet, (unsigned long)msh);
 
-       msh->request = tifm_ms_request;
+       msh->request = tifm_ms_submit_req;
        msh->set_param = tifm_ms_set_param;
        sock->card_event = tifm_ms_card_event;
        sock->data_event = tifm_ms_data_event;
@@ -592,6 +599,8 @@ static void tifm_ms_remove(struct tifm_dev *sock)
        int rc = 0;
        unsigned long flags;
 
+       msh->request = tifm_ms_dummy_submit;
+       tasklet_kill(&host->notify);
        spin_lock_irqsave(&sock->lock, flags);
        host->eject = 1;
        if (host->req) {