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>

diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index 2a7c425ddfa73aef490b7e0fd2b081ebe0ea5926..b2b618f066e02b85c185ba3a17cd1a4ca9e8eaf8 100644 (file)
--- 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]);