We have SSIF interface present in both DMI and ACPI tables, sometimes
ssif_probe is called simultaneously from i2c interface (from ACPI)
and while loading ipmi_ssif driver(from DMI table) at kernel boot.
Both try to register the same SSIF interface simultaneously, where it
hits a race. In this case both send a command and get a currupted response.
This patch adds check to void registering the same device twice.
Signed-off-by: Kamlakant Patel <kamlaka...@marvell.com>
---
drivers/char/ipmi/ipmi_ssif.c | 39 +++++++++++++++++++++++++++++++++++
1 file changed, 39 insertions(+)
diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c
index ca9528c4f183..97830d31c5d3 100644
--- a/drivers/char/ipmi/ipmi_ssif.c
+++ b/drivers/char/ipmi/ipmi_ssif.c
@@ -1146,6 +1146,7 @@ MODULE_PARM_DESC(trydmi, "Setting this to zero will
disable the default scan of
static DEFINE_MUTEX(ssif_infos_mutex);
static LIST_HEAD(ssif_infos);
+static LIST_HEAD(ssif_clients);
#define IPMI_SSIF_ATTR(name) \
static ssize_t ipmi_##name##_show(struct device *dev, \
@@ -1523,6 +1524,34 @@ static void test_multipart_messages(struct i2c_client
*client,
#define GLOBAL_ENABLES_MASK (IPMI_BMC_EVT_MSG_BUFF | IPMI_BMC_RCV_MSG_INTR | \
IPMI_BMC_EVT_MSG_INTR)
+static int ssif_is_registered(struct i2c_client *client)
+{
+ struct ssif_addr_info *info;
+ int rv = 0;
+
+ mutex_lock(&ssif_infos_mutex);
+ list_for_each_entry(info, &ssif_clients, link) {
+ if ((info->binfo.addr == client->addr) &&
+ (!strcmp(info->adapter_name, client->adapter->name))) {
+ rv = -EEXIST;
+ goto exit;
+ }
+ }
+
+ info = kzalloc(sizeof(*info), GFP_KERNEL);
+ if (!info){
+ rv = -ENOMEM;
+ goto exit;
+ }
+
+ info->adapter_name = client->adapter->name;
+ info->binfo.addr = client->addr;
+ list_add_tail(&info->link, &ssif_clients);
+exit:
+ mutex_unlock(&ssif_infos_mutex);
+ return rv;
+}
+
static int ssif_probe(struct i2c_client *client, const struct i2c_device_id
*id)
{
unsigned char msg[3];
@@ -1534,6 +1563,10 @@ static int ssif_probe(struct i2c_client *client, const
struct i2c_device_id *id)
u8 slave_addr = 0;
struct ssif_addr_info *addr_info = NULL;
+ /* Check if the client is already registered. */
+ if (ssif_is_registered(client))
+ return 0;
+
resp = kmalloc(IPMI_MAX_MSG_LENGTH, GFP_KERNEL);
if (!resp)
return -ENOMEM;
@@ -1844,6 +1877,12 @@ static void free_ssif_clients(void)
kfree(info->adapter_name);
kfree(info);
}
+
+ list_for_each_entry_safe(info, tmp, &ssif_clients, link) {
+ list_del(&info->link);
+ kfree(info);
+ }
+
mutex_unlock(&ssif_infos_mutex);
}
--
2.17.1
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