usb: gadget: f_mass_storage: call try_to_freeze only when its safe

Call try_to_freeze() in sleep_thread() only when it's safe to sleep.
do_read() and do_write() calls sleep_thread with lock held.
Make sure these won't call try_to_freeze() by passing can_freeze flag
to sleep_thread.

Calling try_to_freeze() with a lock hold was done since day one in
f_mass_storage but since commit 0f9548ca1 ("lockdep: check that no
locks held at freeze time") lockdep complains about it.

Signed-off-by: George Cherian <george.cherian@ti.com>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 1b2c19b..b963939 100644 (file)
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -602,13 +602,14 @@ static bool start_out_transfer(struct fsg_common *common, struct fsg_buffhd *bh)
        return true;
 }
 
-static int sleep_thread(struct fsg_common *common)
+static int sleep_thread(struct fsg_common *common, bool can_freeze)
 {
        int     rc = 0;
 
        /* Wait until a signal arrives or we are woken up */
        for (;;) {
-               try_to_freeze();
+               if (can_freeze)
+                       try_to_freeze();
                set_current_state(TASK_INTERRUPTIBLE);
                if (signal_pending(current)) {
                        rc = -EINTR;
@@ -682,7 +683,7 @@ static int do_read(struct fsg_common *common)
                /* Wait for the next buffer to become available */
                bh = common->next_buffhd_to_fill;
                while (bh->state != BUF_STATE_EMPTY) {
-                       rc = sleep_thread(common);
+                       rc = sleep_thread(common, false);
                        if (rc)
                                return rc;
                }
@@ -937,7 +938,7 @@ static int do_write(struct fsg_common *common)
                }
 
                /* Wait for something to happen */
-               rc = sleep_thread(common);
+               rc = sleep_thread(common, false);
                if (rc)
                        return rc;
        }
@@ -1504,7 +1505,7 @@ static int throw_away_data(struct fsg_common *common)
                }
 
                /* Otherwise wait for something to happen */
-               rc = sleep_thread(common);
+               rc = sleep_thread(common, true);
                if (rc)
                        return rc;
        }
@@ -1625,7 +1626,7 @@ static int send_status(struct fsg_common *common)
        /* Wait for the next buffer to become available */
        bh = common->next_buffhd_to_fill;
        while (bh->state != BUF_STATE_EMPTY) {
-               rc = sleep_thread(common);
+               rc = sleep_thread(common, true);
                if (rc)
                        return rc;
        }
@@ -1828,7 +1829,7 @@ static int do_scsi_command(struct fsg_common *common)
        bh = common->next_buffhd_to_fill;
        common->next_buffhd_to_drain = bh;
        while (bh->state != BUF_STATE_EMPTY) {
-               rc = sleep_thread(common);
+               rc = sleep_thread(common, true);
                if (rc)
                        return rc;
        }
@@ -2174,7 +2175,7 @@ static int get_next_command(struct fsg_common *common)
        /* Wait for the next buffer to become available */
        bh = common->next_buffhd_to_fill;
        while (bh->state != BUF_STATE_EMPTY) {
-               rc = sleep_thread(common);
+               rc = sleep_thread(common, true);
                if (rc)
                        return rc;
        }
@@ -2193,7 +2194,7 @@ static int get_next_command(struct fsg_common *common)
 
        /* Wait for the CBW to arrive */
        while (bh->state != BUF_STATE_FULL) {
-               rc = sleep_thread(common);
+               rc = sleep_thread(common, true);
                if (rc)
                        return rc;
        }
@@ -2379,7 +2380,7 @@ static void handle_exception(struct fsg_common *common)
                        }
                        if (num_active == 0)
                                break;
-                       if (sleep_thread(common))
+                       if (sleep_thread(common, true))
                                return;
                }
 
@@ -2516,7 +2517,7 @@ static int fsg_main_thread(void *common_)
                }
 
                if (!common->running) {
-                       sleep_thread(common);
+                       sleep_thread(common, true);
                        continue;
                }