sfc: Correct efx_for_each_possible_channel_tx_queue() to skip non-TX channels

efx_for_each_possible_channel_tx_queue() should do nothing for RX-only
or extra channels.  The current definition results in allocating
additional unused hardware TX queues when using the mqprio qdisc and
either separate_tx_channels or SR-IOV.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/net/ethernet/sfc/net_driver.h b/drivers/net/ethernet/sfc/net_driver.h
index 3fbec458c323..0b95505e8968 100644
--- a/drivers/net/ethernet/sfc/net_driver.h
+++ b/drivers/net/ethernet/sfc/net_driver.h
@@ -1030,9 +1030,12 @@ static inline bool efx_tx_queue_used(struct efx_tx_queue *tx_queue)
 
 /* Iterate over all possible TX queues belonging to a channel */
 #define efx_for_each_possible_channel_tx_queue(_tx_queue, _channel)     \
-        for (_tx_queue = (_channel)->tx_queue;                          \
-             _tx_queue < (_channel)->tx_queue + EFX_TXQ_TYPES;          \
-             _tx_queue++)
+        if (!efx_channel_has_tx_queues(_channel))                       \
+                ;                                                       \
+        else                                                            \
+                for (_tx_queue = (_channel)->tx_queue;                  \
+                     _tx_queue < (_channel)->tx_queue + EFX_TXQ_TYPES;  \
+                     _tx_queue++)
 
 static inline bool efx_channel_has_rx_queue(struct efx_channel *channel)
 {