Hello.
On 01/24/2017 09:21 PM, Simon Horman wrote:
From: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx>
"swiotlb buffer is full" errors occur after repeated initialisation of a
device - f.e. suspend/resume or ip link set up/down. This is because memory
mapped using dma_map_single() in ravb_ring_format() and ravb_start_xmit()
is not released. Resolve this problem by unmapping descriptors when
freeing rings.
Note, ravb_tx_free() is moved but not otherwise modified by this patch.
Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx>
[simon: reworked]
Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
--
v3 [Simon Horman]
* As suggested by Sergei Shtylyov
- consistently use le32_to_cpu(desc->dptr)
- Do not clear desc->ds_cc as it is not used
* Paramatise ravb_tx_free() to allow it to free non-transmitted buffers
v2 [Simon Horman]
* As suggested by Sergei Shtylyov
- Use dma_mapping_error() and rx_desc->ds_cc when unmapping RX descriptors;
this is consistent with the way that they are mapped
- Use ravb_tx_free() to clear TX descriptors
* Reduce scope of new local variable
v1 [Kazuya Mizuguchi]
---
drivers/net/ethernet/renesas/ravb_main.c | 113 ++++++++++++++++++-------------
1 file changed, 65 insertions(+), 48 deletions(-)
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 89ac1e3f6175..57fe1411bb9d 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -179,6 +179,51 @@ static struct mdiobb_ops bb_ops = {
.get_mdio_data = ravb_get_mdio_data,
};
+enum ravb_tx_free_mode {
+ ravb_tx_free_all,
+ ravb_tx_free_txed_only,
+};
+
+/* Free TX skb function for AVB-IP */
+static int ravb_tx_free(struct net_device *ndev, int q,
+ enum ravb_tx_free_mode free_mode)
Hmm... Sorry but this looks over-engineered. A *bool* parameter (named e.g
'all) would suffice IMHO.
+{
+ struct ravb_private *priv = netdev_priv(ndev);
+ struct net_device_stats *stats = &priv->stats[q];
+ struct ravb_tx_desc *desc;
+ int free_num = 0;
+ int entry;
+ u32 size;
+
+ for (; priv->cur_tx[q] - priv->dirty_tx[q] > 0; priv->dirty_tx[q]++) {
+ entry = priv->dirty_tx[q] % (priv->num_tx_ring[q] *
+ NUM_TX_DESC);
+ desc = &priv->tx_ring[q][entry];
+ if (free_mode == ravb_tx_free_txed_only &&
+ desc->die_dt != DT_FEMPTY)
+ break;
+ /* Descriptor type must be checked before all other reads */
+ dma_rmb();
+ size = le16_to_cpu(desc->ds_tagl) & TX_DS;
+ /* Free the original skb. */
+ if (priv->tx_skb[q][entry / NUM_TX_DESC]) {
+ dma_unmap_single(ndev->dev.parent, le32_to_cpu(desc->dptr),
+ size, DMA_TO_DEVICE);
+ /* Last packet descriptor? */
+ if (entry % NUM_TX_DESC == NUM_TX_DESC - 1) {
+ entry /= NUM_TX_DESC;
+ dev_kfree_skb_any(priv->tx_skb[q][entry]);
+ priv->tx_skb[q][entry] = NULL;
+ stats->tx_packets++;
+ }
+ free_num++;
+ }
+ stats->tx_bytes += size;
Hmmm... we shouldn't count the discarded unsent packets/bytes as sent, right?
[...]
@@ -215,12 +262,19 @@ static void ravb_ring_free(struct net_device *ndev, int q)
}
if (priv->tx_ring[q]) {
+ ravb_tx_free(ndev, q, ravb_tx_free_all);
+
ring_size = sizeof(struct ravb_tx_desc) *
(priv->num_tx_ring[q] * NUM_TX_DESC + 1);
dma_free_coherent(ndev->dev.parent, ring_size, priv->tx_ring[q],
priv->tx_desc_dma[q]);
priv->tx_ring[q] = NULL;
}
+
+ /* Free TX skb ringbuffer.
+ * SKBs are freed by ravb_tx_free() call above. */
This is not a recommended comment format:
/* bla
* bla
*/
[...]
MBR, Sergei
