uwb: avoid radio controller reset loops

If a radio controller reset attempt occurs while a probe() or remove()
is in progress it fails and is retried endlessly, potentially preventing
the probe() or remove() from completing.

If a reset fails, sleep for a bit before retrying the reset.  This
allows the probe()/remove() to complete.

Signed-off-by: David Vrabel <david.vrabel@csr.com>

1 files changed, 11 insertions, 10 deletions

diff --git a/drivers/uwb/reset.c b/drivers/uwb/reset.c
index 70f8050221ff..7f0512e43d9d 100644
--- a/drivers/uwb/reset.c
+++ b/drivers/uwb/reset.c
@@ -30,6 +30,7 @@
  */
 #include <linux/kernel.h>
 #include <linux/err.h>
+#include <linux/delay.h>
 
 #include "uwb-internal.h"
 
@@ -323,13 +324,15 @@ int uwbd_msg_handle_reset(struct uwb_event *evt)
 
         dev_info(&rc->uwb_dev.dev, "resetting radio controller\n");
         ret = rc->reset(rc);
-        if (ret) {
+        if (ret < 0) {
                 dev_err(&rc->uwb_dev.dev, "failed to reset hardware: %d\n", ret);
                 goto error;
         }
         return 0;
 error:
-        /* Nothing can be done except try the reset again. */
+        /* Nothing can be done except try the reset again. Wait a bit
+           to avoid reset loops during probe() or remove(). */
+        msleep(1000);
         uwb_rc_reset_all(rc);
         return ret;
 }
@@ -368,22 +371,20 @@ void uwb_rc_pre_reset(struct uwb_rc *rc)
 }
 EXPORT_SYMBOL_GPL(uwb_rc_pre_reset);
 
-void uwb_rc_post_reset(struct uwb_rc *rc)
+int uwb_rc_post_reset(struct uwb_rc *rc)
 {
         int ret;
 
         ret = rc->start(rc);
         if (ret)
-                goto error;
+                goto out;
         ret = uwb_rc_mac_addr_set(rc, &rc->uwb_dev.mac_addr);
         if (ret)
-                goto error;
+                goto out;
         ret = uwb_rc_dev_addr_set(rc, &rc->uwb_dev.dev_addr);
         if (ret)
-                goto error;
-        return;
-error:
-        /* Nothing can be done except try the reset again. */
-        uwb_rc_reset_all(rc);
+                goto out;
+out:
+        return ret;
 }
 EXPORT_SYMBOL_GPL(uwb_rc_post_reset);