ipmi_si: use smi_num for init_name

Commit 1abf71e moved the creation of new_smi->dev to earlier in the init
sequence in order to provide infrastructure for log printing.

However, the init_name was created with a hard-coded value of zero. This
presents a problem in systems with more than one interface, producing a
call trace in dmesg.

To correct the problem, simply use smi_num instead of the hard-coded
value of zero.

Tested on a lenovo x3950.

Signed-off-by: Tony Camuso <tcamuso@redhat.com>

There was actually a more general problem, the platform device wasn't
being set correctly, either, and there was a possible (though extremely
unlikely) race on smi_num.  Add locks to clean up the race and use the
proper value for the platform device, too.

Tested on qemu in various configurations.

Signed-off-by: Corey Minyard <cminyard@mvista.com>

1 files changed, 16 insertions, 3 deletions

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 2a7c425ddfa7..b2b618f066e0 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -1954,7 +1954,9 @@ static int hotmod_handler(const char *val, struct kernel_param *kp)
                                 kfree(info);
                                 goto out;
                         }
+                        mutex_lock(&smi_infos_lock);
                         rv = try_smi_init(info);
+                        mutex_unlock(&smi_infos_lock);
                         if (rv) {
                                 cleanup_one_si(info);
                                 goto out;
@@ -2042,8 +2044,10 @@ static int hardcode_find_bmc(void)
                 info->slave_addr = slave_addrs[i];
 
                 if (!add_smi(info)) {
+                        mutex_lock(&smi_infos_lock);
                         if (try_smi_init(info))
                                 cleanup_one_si(info);
+                        mutex_unlock(&smi_infos_lock);
                         ret = 0;
                 } else {
                         kfree(info);
@@ -3492,6 +3496,11 @@ out_err:
         return rv;
 }
 
+/*
+ * Try to start up an interface.  Must be called with smi_infos_lock
+ * held, primarily to keep smi_num consistent, we only one to do these
+ * one at a time.
+ */
 static int try_smi_init(struct smi_info *new_smi)
 {
         int rv = 0;
@@ -3524,9 +3533,12 @@ static int try_smi_init(struct smi_info *new_smi)
                 goto out_err;
         }
 
+        new_smi->intf_num = smi_num;
+
         /* Do this early so it's available for logs. */
         if (!new_smi->dev) {
-                init_name = kasprintf(GFP_KERNEL, "ipmi_si.%d", 0);
+                init_name = kasprintf(GFP_KERNEL, "ipmi_si.%d",
+                                      new_smi->intf_num);
 
                 /*
                  * If we don't already have a device from something
@@ -3593,8 +3605,6 @@ static int try_smi_init(struct smi_info *new_smi)
 
         new_smi->interrupt_disabled = true;
         atomic_set(&new_smi->need_watch, 0);
-        new_smi->intf_num = smi_num;
-        smi_num++;
 
         rv = try_enable_event_buffer(new_smi);
         if (rv == 0)
@@ -3661,6 +3671,9 @@ static int try_smi_init(struct smi_info *new_smi)
                 goto out_err_stop_timer;
         }
 
+        /* Don't increment till we know we have succeeded. */
+        smi_num++;
+
         dev_info(new_smi->dev, "IPMI %s interface initialized\n",
                  si_to_str[new_smi->si_type]);