iwlwifi: do not set tx power when channel is changing

commit f844a709a7d8f8be61a571afc31dfaca9e779621 upstream.

Mac80211 can request for tx power and channel change in one ->config
call. If that happens, *_send_tx_power functions will try to setup tx
power for old channel, what can be not correct because we already change
the band. I.e  error  "Failed to get channel info for channel 140 [0]",
can be printed frequently when operating in software scanning mode.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

4 files changed, 14 insertions, 8 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.c b/drivers/net/wireless/iwlwifi/iwl-3945.c
index 39b6f16c87fa..4e7b58bb1a1b 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -1823,7 +1823,7 @@ int iwl3945_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 
 	/* If we issue a new RXON command which required a tune then we must
 	 * send a new TXPOWER command or we won't be able to Tx any frames */
-	rc = priv->cfg->ops->lib->send_tx_power(priv);
+	rc = iwl_set_tx_power(priv, priv->tx_power_next, true);
 	if (rc) {
 		IWL_ERR(priv, "Error setting Tx power (%d).\n", rc);
 		return rc;
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index 91a9f5253469..992caa0231d0 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -1571,7 +1571,7 @@ static int iwl4965_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *c
 
 	/* If we issue a new RXON command which required a tune then we must
 	 * send a new TXPOWER command or we won't be able to Tx any frames */
-	ret = iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
+	ret = iwl_set_tx_power(priv, priv->tx_power_next, true);
 	if (ret) {
 		IWL_ERR(priv, "Error sending TX power (%d)\n", ret);
 		return ret;
diff --git a/drivers/net/wireless/iwlwifi/iwl-agn-rxon.c b/drivers/net/wireless/iwlwifi/iwl-agn-rxon.c
index 6d140bd53291..ee802fe0e4c4 100644
--- a/drivers/net/wireless/iwlwifi/iwl-agn-rxon.c
+++ b/drivers/net/wireless/iwlwifi/iwl-agn-rxon.c
@@ -288,10 +288,9 @@ int iwlagn_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
 	 * If we issue a new RXON command which required a tune then we must
 	 * send a new TXPOWER command or we won't be able to Tx any frames.
 	 *
-	 * FIXME: which RXON requires a tune? Can we optimise this out in
-	 *        some cases?
+	 * It's expected we set power here if channel is changing.
 	 */
-	ret = iwl_set_tx_power(priv, priv->tx_power_user_lmt, true);
+	ret = iwl_set_tx_power(priv, priv->tx_power_next, true);
 	if (ret) {
 		IWL_ERR(priv, "Error sending TX power (%d)\n", ret);
 		return ret;
diff --git a/drivers/net/wireless/iwlwifi/iwl-core.c b/drivers/net/wireless/iwlwifi/iwl-core.c
index efbde1f1a8bf..91cac6fb41fd 100644
--- a/drivers/net/wireless/iwlwifi/iwl-core.c
+++ b/drivers/net/wireless/iwlwifi/iwl-core.c
@@ -1161,6 +1161,8 @@ int iwl_set_tx_power(struct iwl_priv *priv, s8 tx_power, bool force)
 {
 	int ret;
 	s8 prev_tx_power;
+	bool defer;
+	struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
 
 	lockdep_assert_held(&priv->mutex);
 
@@ -1188,10 +1190,15 @@ int iwl_set_tx_power(struct iwl_priv *priv, s8 tx_power, bool force)
 	if (!iwl_is_ready_rf(priv))
 		return -EIO;
 
-	/* scan complete use tx_power_next, need to be updated */
+	/* scan complete and commit_rxon use tx_power_next value,
+	 * it always need to be updated for newest request */
 	priv->tx_power_next = tx_power;
-	if (test_bit(STATUS_SCANNING, &priv->status) && !force) {
-		IWL_DEBUG_INFO(priv, "Deferring tx power set while scanning\n");
+
+	/* do not set tx power when scanning or channel changing */
+	defer = test_bit(STATUS_SCANNING, &priv->status) ||
+		memcmp(&ctx->active, &ctx->staging, sizeof(ctx->staging));
+	if (defer && !force) {
+		IWL_DEBUG_INFO(priv, "Deferring tx power set\n");
 		return 0;
 	}