]> bbs.cooldavid.org Git - net-next-2.6.git/blobdiff - drivers/usb/gadget/f_mass_storage.c
USB: gadget: f_mass_storage: stale common->fsg value bug fix
[net-next-2.6.git] / drivers / usb / gadget / f_mass_storage.c
index f866b7e72a285c1c8b85f11d9d0d236cb4018c99..4ce899c9b1653b2cfd747e65a17b919d0adeae2c 100644 (file)
@@ -321,8 +321,8 @@ struct fsg_dev;
 /* Data shared by all the FSG instances. */
 struct fsg_common {
        struct usb_gadget       *gadget;
-       struct fsg_dev          *fsg;
-       struct fsg_dev          *prev_fsg;
+       struct fsg_dev          *fsg, *new_fsg;
+       wait_queue_head_t       fsg_wait;
 
        /* filesem protects: backing files in use */
        struct rw_semaphore     filesem;
@@ -351,7 +351,6 @@ struct fsg_common {
        enum fsg_state          state;          /* For exception handling */
        unsigned int            exception_req_tag;
 
-       u8                      config, new_config;
        enum data_direction     data_dir;
        u32                     data_size;
        u32                     data_size_from_cmnd;
@@ -595,7 +594,7 @@ static int fsg_setup(struct usb_function *f,
        u16                     w_value = le16_to_cpu(ctrl->wValue);
        u16                     w_length = le16_to_cpu(ctrl->wLength);
 
-       if (!fsg->common->config)
+       if (!fsg_is_set(fsg->common))
                return -EOPNOTSUPP;
 
        switch (ctrl->bRequest) {
@@ -2303,24 +2302,20 @@ static int alloc_request(struct fsg_common *common, struct usb_ep *ep,
        return -ENOMEM;
 }
 
-/*
- * Reset interface setting and re-init endpoint state (toggle etc).
- * Call with altsetting < 0 to disable the interface.  The only other
- * available altsetting is 0, which enables the interface.
- */
-static int do_set_interface(struct fsg_common *common, int altsetting)
+/* Reset interface setting and re-init endpoint state (toggle etc). */
+static int do_set_interface(struct fsg_common *common, struct fsg_dev *new_fsg)
 {
-       int     rc = 0;
-       int     i;
-       const struct usb_endpoint_descriptor    *d;
+       const struct usb_endpoint_descriptor *d;
+       struct fsg_dev *fsg;
+       int i, rc = 0;
 
        if (common->running)
                DBG(common, "reset interface\n");
 
 reset:
        /* Deallocate the requests */
-       if (common->prev_fsg) {
-               struct fsg_dev *fsg = common->prev_fsg;
+       if (common->fsg) {
+               fsg = common->fsg;
 
                for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
                        struct fsg_buffhd *bh = &common->buffhds[i];
@@ -2345,88 +2340,53 @@ reset:
                        fsg->bulk_out_enabled = 0;
                }
 
-               common->prev_fsg = 0;
+               common->fsg = NULL;
+               wake_up(&common->fsg_wait);
        }
 
        common->running = 0;
-       if (altsetting < 0 || rc != 0)
+       if (!new_fsg || rc)
                return rc;
 
-       DBG(common, "set interface %d\n", altsetting);
+       common->fsg = new_fsg;
+       fsg = common->fsg;
 
-       if (fsg_is_set(common)) {
-               struct fsg_dev *fsg = common->fsg;
-               common->prev_fsg = common->fsg;
+       /* Enable the endpoints */
+       d = fsg_ep_desc(common->gadget,
+                       &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
+       rc = enable_endpoint(common, fsg->bulk_in, d);
+       if (rc)
+               goto reset;
+       fsg->bulk_in_enabled = 1;
+
+       d = fsg_ep_desc(common->gadget,
+                       &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
+       rc = enable_endpoint(common, fsg->bulk_out, d);
+       if (rc)
+               goto reset;
+       fsg->bulk_out_enabled = 1;
+       common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
+       clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
+
+       /* Allocate the requests */
+       for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
+               struct fsg_buffhd       *bh = &common->buffhds[i];
 
-               /* Enable the endpoints */
-               d = fsg_ep_desc(common->gadget,
-                               &fsg_fs_bulk_in_desc, &fsg_hs_bulk_in_desc);
-               rc = enable_endpoint(common, fsg->bulk_in, d);
+               rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
                if (rc)
                        goto reset;
-               fsg->bulk_in_enabled = 1;
-
-               d = fsg_ep_desc(common->gadget,
-                               &fsg_fs_bulk_out_desc, &fsg_hs_bulk_out_desc);
-               rc = enable_endpoint(common, fsg->bulk_out, d);
+               rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
                if (rc)
                        goto reset;
-               fsg->bulk_out_enabled = 1;
-               common->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
-               clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
-
-               /* Allocate the requests */
-               for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-                       struct fsg_buffhd       *bh = &common->buffhds[i];
-
-                       rc = alloc_request(common, fsg->bulk_in, &bh->inreq);
-                       if (rc)
-                               goto reset;
-                       rc = alloc_request(common, fsg->bulk_out, &bh->outreq);
-                       if (rc)
-                               goto reset;
-                       bh->inreq->buf = bh->outreq->buf = bh->buf;
-                       bh->inreq->context = bh->outreq->context = bh;
-                       bh->inreq->complete = bulk_in_complete;
-                       bh->outreq->complete = bulk_out_complete;
-               }
-
-               common->running = 1;
-               for (i = 0; i < common->nluns; ++i)
-                       common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
-               return rc;
-       } else {
-               return -EIO;
+               bh->inreq->buf = bh->outreq->buf = bh->buf;
+               bh->inreq->context = bh->outreq->context = bh;
+               bh->inreq->complete = bulk_in_complete;
+               bh->outreq->complete = bulk_out_complete;
        }
-}
 
-
-/*
- * Change our operational configuration.  This code must agree with the code
- * that returns config descriptors, and with interface altsetting code.
- *
- * It's also responsible for power management interactions.  Some
- * configurations might not work with our current power sources.
- * For now we just assume the gadget is always self-powered.
- */
-static int do_set_config(struct fsg_common *common, u8 new_config)
-{
-       int     rc = 0;
-
-       /* Disable the single interface */
-       if (common->config != 0) {
-               DBG(common, "reset config\n");
-               common->config = 0;
-               rc = do_set_interface(common, -1);
-       }
-
-       /* Enable the interface */
-       if (new_config != 0) {
-               common->config = new_config;
-               rc = do_set_interface(common, 0);
-               if (rc != 0)
-                       common->config = 0;     /* Reset on errors */
-       }
+       common->running = 1;
+       for (i = 0; i < common->nluns; ++i)
+               common->luns[i].unit_attention_data = SS_RESET_OCCURRED;
        return rc;
 }
 
@@ -2437,9 +2397,7 @@ static int do_set_config(struct fsg_common *common, u8 new_config)
 static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 {
        struct fsg_dev *fsg = fsg_from_func(f);
-       fsg->common->prev_fsg = fsg->common->fsg;
-       fsg->common->fsg = fsg;
-       fsg->common->new_config = 1;
+       fsg->common->new_fsg = fsg;
        raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
        return 0;
 }
@@ -2447,9 +2405,7 @@ static int fsg_set_alt(struct usb_function *f, unsigned intf, unsigned alt)
 static void fsg_disable(struct usb_function *f)
 {
        struct fsg_dev *fsg = fsg_from_func(f);
-       fsg->common->prev_fsg = fsg->common->fsg;
-       fsg->common->fsg = fsg;
-       fsg->common->new_config = 0;
+       fsg->common->new_fsg = NULL;
        raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
 }
 
@@ -2459,19 +2415,17 @@ static void fsg_disable(struct usb_function *f)
 static void handle_exception(struct fsg_common *common)
 {
        siginfo_t               info;
-       int                     sig;
        int                     i;
        struct fsg_buffhd       *bh;
        enum fsg_state          old_state;
-       u8                      new_config;
        struct fsg_lun          *curlun;
        unsigned int            exception_req_tag;
-       int                     rc;
 
        /* Clear the existing signals.  Anything but SIGUSR1 is converted
         * into a high-priority EXIT exception. */
        for (;;) {
-               sig = dequeue_signal_lock(current, &current->blocked, &info);
+               int sig =
+                       dequeue_signal_lock(current, &current->blocked, &info);
                if (!sig)
                        break;
                if (sig != SIGUSR1) {
@@ -2482,7 +2436,7 @@ static void handle_exception(struct fsg_common *common)
        }
 
        /* Cancel all the pending transfers */
-       if (fsg_is_set(common)) {
+       if (likely(common->fsg)) {
                for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
                        bh = &common->buffhds[i];
                        if (bh->inreq_busy)
@@ -2523,7 +2477,6 @@ static void handle_exception(struct fsg_common *common)
        common->next_buffhd_to_fill = &common->buffhds[0];
        common->next_buffhd_to_drain = &common->buffhds[0];
        exception_req_tag = common->exception_req_tag;
-       new_config = common->new_config;
        old_state = common->state;
 
        if (old_state == FSG_STATE_ABORT_BULK_OUT)
@@ -2573,12 +2526,12 @@ static void handle_exception(struct fsg_common *common)
                break;
 
        case FSG_STATE_CONFIG_CHANGE:
-               rc = do_set_config(common, new_config);
+               do_set_interface(common, common->new_fsg);
                break;
 
        case FSG_STATE_EXIT:
        case FSG_STATE_TERMINATED:
-               do_set_config(common, 0);               /* Free resources */
+               do_set_interface(common, NULL);         /* Free resources */
                spin_lock_irq(&common->lock);
                common->state = FSG_STATE_TERMINATED;   /* Stop the thread */
                spin_unlock_irq(&common->lock);
@@ -2863,6 +2816,7 @@ buffhds_first_it:
                goto error_release;
        }
        init_completion(&common->thread_notifier);
+       init_waitqueue_head(&common->fsg_wait);
 #undef OR
 
 
@@ -2957,9 +2911,17 @@ static void fsg_common_release(struct kref *ref)
 static void fsg_unbind(struct usb_configuration *c, struct usb_function *f)
 {
        struct fsg_dev          *fsg = fsg_from_func(f);
+       struct fsg_common       *common = fsg->common;
 
        DBG(fsg, "unbind\n");
-       fsg_common_put(fsg->common);
+       if (fsg->common->fsg == fsg) {
+               fsg->common->new_fsg = NULL;
+               raise_exception(fsg->common, FSG_STATE_CONFIG_CHANGE);
+               /* FIXME: make interruptible or killable somehow? */
+               wait_event(common->fsg_wait, common->fsg != fsg);
+       }
+
+       fsg_common_put(common);
        usb_free_descriptors(fsg->function.descriptors);
        usb_free_descriptors(fsg->function.hs_descriptors);
        kfree(fsg);