[PATCH 1/5] rapidio: fix blocking wait for discovery ready

From: Alexandre Bounine
Date: Wed Oct 03 2012 - 15:26:19 EST


Fix blocking wait loop in the RapidIO discovery routine to avoid warning
dumps about stalled CPU on x86 platforms.

Signed-off-by: Alexandre Bounine <alexandre.bounine@xxxxxxx>
Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
Cc: Li Yang <leoli@xxxxxxxxxxxxx>
---
drivers/rapidio/rio-scan.c | 62 ++++++++++++++-----------------------------
1 files changed, 20 insertions(+), 42 deletions(-)

diff --git a/drivers/rapidio/rio-scan.c b/drivers/rapidio/rio-scan.c
index 02e686b..0a27253 100644
--- a/drivers/rapidio/rio-scan.c
+++ b/drivers/rapidio/rio-scan.c
@@ -31,6 +31,7 @@
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
+#include <linux/sched.h>
#include <linux/jiffies.h>
#include <linux/slab.h>

@@ -39,8 +40,6 @@
LIST_HEAD(rio_devices);
static LIST_HEAD(rio_switches);

-static void rio_enum_timeout(unsigned long);
-
static void rio_init_em(struct rio_dev *rdev);

DEFINE_SPINLOCK(rio_global_list_lock);
@@ -49,9 +48,6 @@ static int next_destid = 0;
static int next_net = 0;
static int next_comptag = 1;

-static struct timer_list rio_enum_timer =
-TIMER_INITIALIZER(rio_enum_timeout, 0, 0);
-
static int rio_mport_phys_table[] = {
RIO_EFB_PAR_EP_ID,
RIO_EFB_PAR_EP_REC_ID,
@@ -1234,20 +1230,6 @@ static void rio_build_route_tables(void)
}

/**
- * rio_enum_timeout- Signal that enumeration timed out
- * @data: Address of timeout flag.
- *
- * When the enumeration complete timer expires, set a flag that
- * signals to the discovery process that enumeration did not
- * complete in a sane amount of time.
- */
-static void rio_enum_timeout(unsigned long data)
-{
- /* Enumeration timed out, set flag */
- *(int *)data = 1;
-}
-
-/**
* rio_disc_mport- Start discovery through a master port
* @mport: Master port to send transactions
*
@@ -1260,34 +1242,33 @@ static void rio_enum_timeout(unsigned long data)
int __devinit rio_disc_mport(struct rio_mport *mport)
{
struct rio_net *net = NULL;
- int enum_timeout_flag = 0;
+ unsigned long to_end;

printk(KERN_INFO "RIO: discover master port %d, %s\n", mport->id,
mport->name);

/* If master port has an active link, allocate net and discover peers */
if (rio_mport_is_active(mport)) {
- if (!(net = rio_alloc_net(mport))) {
- printk(KERN_ERR "RIO: Failed to allocate new net\n");
- goto bail;
- }
+ pr_debug("RIO: wait for enumeration to complete...\n");

- pr_debug("RIO: wait for enumeration complete...");
-
- rio_enum_timer.expires =
- jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
- rio_enum_timer.data = (unsigned long)&enum_timeout_flag;
- add_timer(&rio_enum_timer);
- while (!rio_enum_complete(mport)) {
- mdelay(1);
- if (enum_timeout_flag) {
- del_timer_sync(&rio_enum_timer);
- goto timeout;
- }
+ to_end = jiffies + CONFIG_RAPIDIO_DISC_TIMEOUT * HZ;
+ while (time_before(jiffies, to_end)) {
+ if (rio_enum_complete(mport))
+ goto enum_done;
+ schedule_timeout_uninterruptible(msecs_to_jiffies(10));
}
- del_timer_sync(&rio_enum_timer);

- pr_debug("done\n");
+ pr_debug("RIO: discovery timeout on mport %d %s\n",
+ mport->id, mport->name);
+ goto bail;
+enum_done:
+ pr_debug("RIO: ... enumeration done\n");
+
+ net = rio_alloc_net(mport);
+ if (!net) {
+ printk(KERN_ERR "RIO: Failed to allocate new net\n");
+ goto bail;
+ }

/* Read DestID assigned by enumerator */
rio_local_read_config_32(mport, RIO_DID_CSR,
@@ -1307,9 +1288,6 @@ int __devinit rio_disc_mport(struct rio_mport *mport)
}

return 0;
-
- timeout:
- pr_debug("timeout\n");
- bail:
+bail:
return -EBUSY;
}
--
1.7.8.4

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