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| author | Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> | 2021-09-07 20:29:40 +0900 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-09-22 12:28:06 +0200 |
| commit | 47bc9c3929eb0bafe805bf87474615c8596d16bc (patch) | |
| tree | 143db66c597c88f43c38745f1f48b47eb2325a7a | |
| parent | b2f9b7455baf8ba12113520cdf0398b6141ae42f (diff) | |
| download | linux-stable-47bc9c3929eb0bafe805bf87474615c8596d16bc.tar.gz linux-stable-47bc9c3929eb0bafe805bf87474615c8596d16bc.tar.bz2 linux-stable-47bc9c3929eb0bafe805bf87474615c8596d16bc.zip | |
net: renesas: sh_eth: Fix freeing wrong tx descriptor
[ Upstream commit 0341d5e3d1ee2a36dd5a49b5bef2ce4ad1cfa6b4 ]
The cur_tx counter must be incremented after TACT bit of
txdesc->status was set. However, a CPU is possible to reorder
instructions and/or memory accesses between cur_tx and
txdesc->status. And then, if TX interrupt happened at such a
timing, the sh_eth_tx_free() may free the descriptor wrongly.
So, add wmb() before cur_tx++.
Otherwise NETDEV WATCHDOG timeout is possible to happen.
Fixes: 86a74ff21a7a ("net: sh_eth: add support for Renesas SuperH Ethernet")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/net/ethernet/renesas/sh_eth.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c index 5cab2d3c0023..8927d5997745 100644 --- a/drivers/net/ethernet/renesas/sh_eth.c +++ b/drivers/net/ethernet/renesas/sh_eth.c @@ -2533,6 +2533,7 @@ static netdev_tx_t sh_eth_start_xmit(struct sk_buff *skb, else txdesc->status |= cpu_to_le32(TD_TACT); + wmb(); /* cur_tx must be incremented after TACT bit was set */ mdp->cur_tx++; if (!(sh_eth_read(ndev, EDTRR) & mdp->cd->edtrr_trns)) |