iwlwifi: always copy first 16 bytes of commands

The FH hardware will always write back to the scratch field
in commands, even host commands not just TX commands, which
can overwrite parts of the command. This is problematic if
the command is re-used (with IWL_HCMD_DFL_NOCOPY) and can
cause calibration issues.

Address this problem by always putting at least the first
16 bytes into the buffer we also use for the command header
and therefore make the DMA engine write back into this.

For commands that are smaller than 16 bytes also always map
enough memory for the DMA engine to write back to.

Cc: stable@vger.kernel.org
Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 4 insertions, 6 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-devtrace.h b/drivers/net/wireless/iwlwifi/iwl-devtrace.h
index 9a0f45e..10f0179 100644
--- a/drivers/net/wireless/iwlwifi/iwl-devtrace.h
+++ b/drivers/net/wireless/iwlwifi/iwl-devtrace.h
@@ -349,25 +349,23 @@ TRACE_EVENT(iwlwifi_dev_rx_data,
 TRACE_EVENT(iwlwifi_dev_hcmd,
 	TP_PROTO(const struct device *dev,
 		 struct iwl_host_cmd *cmd, u16 total_size,
-		 const void *hdr, size_t hdr_len),
-	TP_ARGS(dev, cmd, total_size, hdr, hdr_len),
+		 struct iwl_cmd_header *hdr),
+	TP_ARGS(dev, cmd, total_size, hdr),
 	TP_STRUCT__entry(
 		DEV_ENTRY
 		__dynamic_array(u8, hcmd, total_size)
 		__field(u32, flags)
 	),
 	TP_fast_assign(
-		int i, offset = hdr_len;
+		int i, offset = sizeof(*hdr);
 
 		DEV_ASSIGN;
 		__entry->flags = cmd->flags;
-		memcpy(__get_dynamic_array(hcmd), hdr, hdr_len);
+		memcpy(__get_dynamic_array(hcmd), hdr, sizeof(*hdr));
 
 		for (i = 0; i < IWL_MAX_CMD_TFDS; i++) {
 			if (!cmd->len[i])
 				continue;
-			if (!(cmd->dataflags[i] & IWL_HCMD_DFL_NOCOPY))
-				continue;
 			memcpy((u8 *)__get_dynamic_array(hcmd) + offset,
 			       cmd->data[i], cmd->len[i]);
 			offset += cmd->len[i];