Hi Dalon,
On 12/13/18 11:52 AM, dwest...@gmail.com wrote:
From: Dalon Westergreen <dalon.westergr...@intel.com>
The return from tx_buffer call in tse_start_xmit is
inapropriately ignored. tse_buffer calls should return
0 for success or NETDEV_TX_BUSY. tse_start_xmit should
return not report a successful transmit when the tse_buffer
call returns an error condition.
In addition to the above, the msgdma and sgdma do not return
the same value on success or failure. The sgdma_tx_buffer
returned 0 on failure and a positive number of transmitted
packets on success. Given that it only ever sends 1 packet,
this made no sense. The msgdma implementation msgdma_tx_buffer
returns 0 on success.
-> Don't ignore the return from tse_buffer calls
-> Fix sgdma tse_buffer call to return 0 on success
and NETDEV_TX_BUSY on failure.
Signed-off-by: Dalon Westergreen <dalon.westergr...@intel.com>
---
drivers/net/ethernet/altera/altera_sgdma.c | 14 ++++++++------
drivers/net/ethernet/altera/altera_tse_main.c | 4 +++-
2 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/net/ethernet/altera/altera_sgdma.c
b/drivers/net/ethernet/altera/altera_sgdma.c
index 88ef67a998b4..eb47b9b820bb 100644
--- a/drivers/net/ethernet/altera/altera_sgdma.c
+++ b/drivers/net/ethernet/altera/altera_sgdma.c
@@ -15,6 +15,7 @@
*/
#include <linux/list.h>
+#include <linux/netdevice.h>
#include "altera_utils.h"
#include "altera_tse.h"
#include "altera_sgdmahw.h"
@@ -170,10 +171,11 @@ void sgdma_clear_txirq(struct altera_tse_private *priv)
SGDMA_CTRLREG_CLRINT);
}
-/* transmits buffer through SGDMA. Returns number of buffers
- * transmitted, 0 if not possible.
- *
- * tx_lock is held by the caller
+/* transmits buffer through SGDMA.
+ * original behavior returned the number of transmitted packets (always 1) &
+ * returned 0 on error. This differs from the msgdma. the calling function
+ * will now actually look at the code, so from now, 0 is good and return
+ * NETDEV_TX_BUSY when busy.
*/
int sgdma_tx_buffer(struct altera_tse_private *priv, struct tse_buffer
*buffer)
{
@@ -185,7 +187,7 @@ int sgdma_tx_buffer(struct altera_tse_private *priv, struct
tse_buffer *buffer)
/* wait 'til the tx sgdma is ready for the next transmit request */
if (sgdma_txbusy(priv))
- return 0;
+ return NETDEV_TX_BUSY;
sgdma_setup_descrip(cdesc, /* current descriptor */
ndesc, /* next descriptor */
@@ -202,7 +204,7 @@ int sgdma_tx_buffer(struct altera_tse_private *priv, struct
tse_buffer *buffer)
/* enqueue the request to the pending transmit queue */
queue_tx(priv, buffer);
- return 1;
+ return 0;
}
diff --git a/drivers/net/ethernet/altera/altera_tse_main.c b/drivers/net/ethernet/altera/altera_tse_main.c
index baca8f704a45..dcb330129e23 100644
--- a/drivers/net/ethernet/altera/altera_tse_main.c
+++ b/drivers/net/ethernet/altera/altera_tse_main.c
@@ -606,7 +606,9 @@ static int tse_start_xmit(struct sk_buff *skb, struct
net_device *dev)
buffer->dma_addr = dma_addr;
buffer->len = nopaged_len;
- priv->dmaops->tx_buffer(priv, buffer);
+ ret = priv->dmaops->tx_buffer(priv, buffer);
+ if (ret)
+ goto out;
skb_tx_timestamp(skb);
If the content hasn't changed, you can just include my previous Acked-by
under your Signed-off-by in the subsequent versions. For now though,
Acked-by: Thor Thayer <thor.tha...@linux.intel.com>
