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>
diff --git a/drivers/uwb/hwa-rc.c b/drivers/uwb/hwa-rc.c
index 9052bcb..e7eeb63 100644
--- a/drivers/uwb/hwa-rc.c
+++ b/drivers/uwb/hwa-rc.c
@@ -887,8 +887,7 @@
struct hwarc *hwarc = usb_get_intfdata(iface);
struct uwb_rc *uwb_rc = hwarc->uwb_rc;
- uwb_rc_post_reset(uwb_rc);
- return 0;
+ return uwb_rc_post_reset(uwb_rc);
}
/** USB device ID's that we handle */
diff --git a/drivers/uwb/reset.c b/drivers/uwb/reset.c
index 70f8050..7f0512e 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 @@
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 @@
}
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);
diff --git a/drivers/uwb/umc-bus.c b/drivers/uwb/umc-bus.c
index 5ad3616..cdd6c8e 100644
--- a/drivers/uwb/umc-bus.c
+++ b/drivers/uwb/umc-bus.c
@@ -66,7 +66,7 @@
return -EAGAIN;
ret = device_for_each_child(parent, parent, umc_bus_pre_reset_helper);
if (ret >= 0)
- device_for_each_child(parent, parent, umc_bus_post_reset_helper);
+ ret = device_for_each_child(parent, parent, umc_bus_post_reset_helper);
up(&parent->sem);
return ret;
diff --git a/drivers/uwb/whc-rc.c b/drivers/uwb/whc-rc.c
index 19a1dd1..1d9a6f5 100644
--- a/drivers/uwb/whc-rc.c
+++ b/drivers/uwb/whc-rc.c
@@ -443,8 +443,7 @@
struct whcrc *whcrc = umc_get_drvdata(umc);
struct uwb_rc *uwb_rc = whcrc->uwb_rc;
- uwb_rc_post_reset(uwb_rc);
- return 0;
+ return uwb_rc_post_reset(uwb_rc);
}
/* PCI device ID's that we handle [so it gets loaded] */
diff --git a/include/linux/uwb.h b/include/linux/uwb.h
index c021289..7fc9746 100644
--- a/include/linux/uwb.h
+++ b/include/linux/uwb.h
@@ -597,7 +597,7 @@
void uwb_rc_neh_error(struct uwb_rc *, int);
void uwb_rc_reset_all(struct uwb_rc *rc);
void uwb_rc_pre_reset(struct uwb_rc *rc);
-void uwb_rc_post_reset(struct uwb_rc *rc);
+int uwb_rc_post_reset(struct uwb_rc *rc);
/**
* uwb_rsv_is_owner - is the owner of this reservation the RC?