Hello!
On 4/16/2017 11:01 PM, Sergei Shtylyov wrote:
The DMA API debugging (when enabled) causes:
WARNING: CPU: 0 PID: 1445 at lib/dma-debug.c:519 add_dma_entry+0xe0/0x12c
DMA-API: exceeded 7 overlapping mappings of cacheline 0x01b2974d
to be printed after repeated initialization of the Ether device, e.g.
suspend/resume or 'ifconfig' up/down. This is because DMA buffers mapped
using dma_map_single() in sh_eth_ring_format() and sh_eth_start_xmit() are
never unmapped. Resolve this problem by unmapping the buffers when freeing
the descriptor rings; in order to do it right, we'd have to add an extra
parameter to sh_eth_txfree() (we rename this function to sh_eth_tx_free(),
while at it).
Based on the commit a47b70ea86bd ("ravb: unmap descriptors when freeing
rings").
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@xxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/renesas/sh_eth.c | 122 ++++++++++++++++++----------------
1 file changed, 67 insertions(+), 55 deletions(-)
Index: net/drivers/net/ethernet/renesas/sh_eth.c
===================================================================
--- net.orig/drivers/net/ethernet/renesas/sh_eth.c
+++ net/drivers/net/ethernet/renesas/sh_eth.c
@@ -1127,12 +1127,70 @@ static struct mdiobb_ops bb_ops = {
.get_mdio_data = sh_get_mdio,
};
+/* free Tx skb function */
+static int sh_eth_tx_free(struct net_device *ndev, bool sent_only)
+{
+ struct sh_eth_private *mdp = netdev_priv(ndev);
+ struct sh_eth_txdesc *txdesc;
+ int free_num = 0;
+ int entry;
+ bool sent;
+
+ for (; mdp->cur_tx - mdp->dirty_tx > 0; mdp->dirty_tx++) {
+ entry = mdp->dirty_tx % mdp->num_tx_ring;
+ txdesc = &mdp->tx_ring[entry];
+ sent = txdesc->status & cpu_to_le32(TD_TACT);
Oops, forgot to reverse the condition here. Which means I haven't goved in
enough testing... :-/
+ if (sent_only && !sent)
+ break;
[...]
MBR, Sergei
