Patch "iwlwifi: mvm: use IWL_HCMD_NOCOPY for MCAST_FILTER_CMD" has been added to the 4.4-stable tree

This is a note to let you know that I've just added the patch titled

iwlwifi: mvm: use IWL_HCMD_NOCOPY for MCAST_FILTER_CMD

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
iwlwifi-mvm-use-iwl_hcmd_nocopy-for-mcast_filter_cmd.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Luca Coelho <[email protected]>
Date: Fri, 1 Sep 2017 17:59:15 +0300
Subject: iwlwifi: mvm: use IWL_HCMD_NOCOPY for MCAST_FILTER_CMD

From: Luca Coelho <[email protected]>

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/intel/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

---
 drivers/net/wireless/iwlwifi/mvm/mac80211.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

@@ -1906,6 +1906,11 @@ 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 */

@@ -1920,7 +1925,10 @@ 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);
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/iwlwifi-mvm-use-iwl_hcmd_nocopy-for-mcast_filter_cmd.patch