On Thu, Jan 26, 2017 at 03:58:45PM +0300, Sergei Shtylyov wrote:
> On 01/26/2017 02:04 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.
> >
> >Fixes: a780893c89f6 ("ravb: unmap descriptors when freeing rings")
>
> No such SHA1 hash known and the summary is from this patch.
Sorry, it took the HEAD commit rather than a hash I should have provided
as an argument to git fixes:
[alias]
fixes = log -1 --pretty=fixes
[core]
abbrev = 12
[pretty]
fixes = Fixes: %h (\"%s\")
What I wanted to say was:
Fixes: c156633f1353 ("Renesas Ethernet AVB driver proper")
> >Signed-off-by: Kazuya Mizuguchi <kazuya.mizuguchi.ks@xxxxxxxxxxx>
> >[simon: reworked]
> >Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> >--
> >
> >On inspection it appears that a similar problem is also present in
> >the SH-Ethernet driver.
> >
> >v4 [Simon Horman]
> >* As suggested by Sergei Shtylyov
> > - Use bool as type for new parameter to ravb_tx_free()
> > - Clean up comment style
> > - Only increment tx_bytes for transmitted skbs
> >
> >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 | 111 ++++++++++++++++++-------------
> > 1 file changed, 63 insertions(+), 48 deletions(-)
> >
> >diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
> >index 89ac1e3f6175..5d66ac721335 100644
> >--- a/drivers/net/ethernet/renesas/ravb_main.c
> >+++ b/drivers/net/ethernet/renesas/ravb_main.c
> >@@ -179,6 +179,48 @@ static struct mdiobb_ops bb_ops = {
> > .get_mdio_data = ravb_get_mdio_data,
> > };
> >
> >+/* Free TX skb function for AVB-IP */
> >+static int ravb_tx_free(struct net_device *ndev, int q, bool free_txed_only)
> >+{
> >+ 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]++) {
> >+ bool txed;
> >+
> >+ entry = priv->dirty_tx[q] % (priv->num_tx_ring[q] *
> >+ NUM_TX_DESC);
> >+ desc = &priv->tx_ring[q][entry];
> >+ txed = desc->die_dt == DT_FEMPTY;
> >+ if (free_txed_only && !txed)
> >+ 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++;
>
> We're still incrementing the packet # even when the packet hasn't been sent...
Thanks, sorry for missing that.
> >+ }
> >+ free_num++;
> >+ }
> >+ if (!txed)
>
> Your logic is reversed! :-(
Oops.
> >+ stats->tx_bytes += size;
> >+ desc->die_dt = DT_EEMPTY;
> >+ }
> >+ return free_num;
> >+}
> >+
> > /* Free skb's and DMA buffers for Ethernet AVB */
> > static void ravb_ring_free(struct net_device *ndev, int q)
> > {
> >@@ -194,19 +236,21 @@ static void ravb_ring_free(struct net_device *ndev, int q)
> [...]
> >
> > if (priv->rx_ring[q]) {
> >+ for (i = 0; i < priv->num_rx_ring[q]; i++) {
> >+ struct ravb_ex_rx_desc *desc = &priv->rx_ring[q][i];
> >+
> >+ if (!dma_mapping_error(ndev->dev.parent,
> >+ le32_to_cpu(desc->dptr)))
>
> I'd check for zero buffer length (that marks unmapped RX buffers) but
> this should be good too... it's just that the length check is shorter. :-)
I'm pretty sure you suggested the logic above at some point.
Lets keep it :)
> >+ dma_unmap_single(ndev->dev.parent,
> >+ le32_to_cpu(desc->dptr),
> >+ PKT_BUF_SZ,
> >+ DMA_FROM_DEVICE);
> >+ }
> > ring_size = sizeof(struct ravb_ex_rx_desc) *
> > (priv->num_rx_ring[q] + 1);
> > dma_free_coherent(ndev->dev.parent, ring_size, priv->rx_ring[q],
> [...]
>
> MBR, Sergei
>
