[PATCH 3.16 003/204] iwlwifi: mvm: use IWL_HCMD_NOCOPY for MCAST_FILTER_CMD

[Ben Hutchings]

3.16.52-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Luca Coelho <luciano.coelho@xxxxxxxxx>

commit 97bce57bd7f96e1218751996f549a6e61f18cc8c upstream.

The MCAST_FILTER_CMD can get quite large when we have many mcast
addresses to set (we support up to 255).  So the command should be
send as NOCOPY to prevent a warning caused by too-long commands:

WARNING: CPU: 0 PID: 9700 at /root/iwlwifi/stack-dev/drivers/net/wireless/iwlwifi/pcie/tx.c:1550 iwl_pcie_enqueue_hcmd+0x8c7/0xb40 [iwlwifi]
Command MCAST_FILTER_CMD (0x1d0) is too large (328 bytes)

This fixes: https://bugzilla.kernel.org/show_bug.cgi?id=196743

Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/net/wireless/iwlwifi/mvm/mac80211.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -1004,6 +1004,11 @@ static void iwl_mvm_mc_iface_iterator(vo
 	struct iwl_mvm_mc_iter_data *data = _data;
 	struct iwl_mvm *mvm = data->mvm;
 	struct iwl_mcast_filter_cmd *cmd = mvm->mcast_filter_cmd;
+	struct iwl_host_cmd hcmd = {
+		.id = MCAST_FILTER_CMD,
+		.flags = CMD_ASYNC,
+		.dataflags[0] = IWL_HCMD_DFL_NOCOPY,
+	};
 	int ret, len;
 
 	/* if we don't have free ports, mcast frames will be dropped */
@@ -1018,7 +1023,10 @@ static void iwl_mvm_mc_iface_iterator(vo
 	memcpy(cmd->bssid, vif->bss_conf.bssid, ETH_ALEN);
 	len = roundup(sizeof(*cmd) + cmd->count * ETH_ALEN, 4);
 
-	ret = iwl_mvm_send_cmd_pdu(mvm, MCAST_FILTER_CMD, CMD_ASYNC, len, cmd);
+	hcmd.len[0] = len;
+	hcmd.data[0] = cmd;
+
+	ret = iwl_mvm_send_cmd(mvm, &hcmd);
 	if (ret)
 		IWL_ERR(mvm, "mcast filter cmd error. ret=%d\n", ret);
 }