cxgb4: fix panic when attaching to ULD fail

Release resources when attaching to ULD fail. Otherwise, data
mismatch is seen between LLD and ULD later on, which lead to
kernel panic when accessing resources that should not even
exist in the first place.

Fixes: 94cdb8bb ("cxgb4: Add support for dynamic allocation of resources for ULD")
Signed-off-by: Shahjada Abul Husain <shahjada@chelsio.com>
Signed-off-by: Vishal Kulkarni <vishal@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/chelsio/cxgb4/cxgb4_uld.c

@@ -695,10 +695,10 @@ static void uld_init(struct adapter *adap, struct cxgb4_lld_info *lld)
 	lld->write_cmpl_support = adap->params.write_cmpl_support;
 }
 
-static void uld_attach(struct adapter *adap, unsigned int uld)
+static int uld_attach(struct adapter *adap, unsigned int uld)
 {
-	void *handle;
 	struct cxgb4_lld_info lli;
+	void *handle;
 
 	uld_init(adap, &lli);
 	uld_queue_init(adap, uld, &lli);
@@ -708,7 +708,7 @@ static void uld_attach(struct adapter *adap, unsigned int uld)
 		dev_warn(adap->pdev_dev,
 			 "could not attach to the %s driver, error %ld\n",
 			 adap->uld[uld].name, PTR_ERR(handle));
-		return;
+		return PTR_ERR(handle);
 	}
 
 	adap->uld[uld].handle = handle;
@@ -716,22 +716,22 @@ static void uld_attach(struct adapter *adap, unsigned int uld)
 
 	if (adap->flags & CXGB4_FULL_INIT_DONE)
 		adap->uld[uld].state_change(handle, CXGB4_STATE_UP);
+
+	return 0;
 }
 
-/**
- *	cxgb4_register_uld - register an upper-layer driver
+/* cxgb4_register_uld - register an upper-layer driver
  * @type: the ULD type
  * @p: the ULD methods
  *
  * Registers an upper-layer driver with this driver and notifies the ULD
- *	about any presently available devices that support its type.  Returns
- *	%-EBUSY if a ULD of the same type is already registered.
+ * about any presently available devices that support its type.
  */
 void cxgb4_register_uld(enum cxgb4_uld type,
 			const struct cxgb4_uld_info *p)
 {
-	int ret = 0;
 	struct adapter *adap;
+	int ret = 0;
 
 	if (type >= CXGB4_ULD_MAX)
 		return;
@@ -763,8 +763,12 @@ void cxgb4_register_uld(enum cxgb4_uld type,
 		if (ret)
 			goto free_irq;
 		adap->uld[type] = *p;
-		uld_attach(adap, type);
+		ret = uld_attach(adap, type);
+		if (ret)
+			goto free_txq;
 		continue;
+free_txq:
+		release_sge_txq_uld(adap, type);
 free_irq:
 		if (adap->flags & CXGB4_FULL_INIT_DONE)
 			quiesce_rx_uld(adap, type);