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author | Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> | 2020-07-21 09:23:12 +0300 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-08-05 10:59:50 +0300 |
commit | df366abb9c8f4c852b0bca9691810be9335fa153 (patch) | |
tree | be63e45366f46ccd8fbfec10c0f4b6e7b4ac8978 | |
parent | ac7c3b8f34ec6bad54f83ccb2ecf86a6f82d5fdc (diff) | |
download | linux-df366abb9c8f4c852b0bca9691810be9335fa153.tar.xz |
net: ethernet: ravb: exit if re-initialization fails in tx timeout
[ Upstream commit 015c5d5e6aa3523c758a70eb87b291cece2dbbb4 ]
According to the report of [1], this driver is possible to cause
the following error in ravb_tx_timeout_work().
ravb e6800000.ethernet ethernet: failed to switch device to config mode
This error means that the hardware could not change the state
from "Operation" to "Configuration" while some tx and/or rx queue
are operating. After that, ravb_config() in ravb_dmac_init() will fail,
and then any descriptors will be not allocaled anymore so that NULL
pointer dereference happens after that on ravb_start_xmit().
To fix the issue, the ravb_tx_timeout_work() should check
the return values of ravb_stop_dma() and ravb_dmac_init().
If ravb_stop_dma() fails, ravb_tx_timeout_work() re-enables TX and RX
and just exits. If ravb_dmac_init() fails, just exits.
[1]
https://lore.kernel.org/linux-renesas-soc/20200518045452.2390-1-dirk.behme@de.bosch.com/
Reported-by: Dirk Behme <dirk.behme@de.bosch.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Sergei Shtylyov <sergei.shtylyov@gmail.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/ravb_main.c | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index 3f165c137236..30cdabf64ccc 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -1444,6 +1444,7 @@ static void ravb_tx_timeout_work(struct work_struct *work) struct ravb_private *priv = container_of(work, struct ravb_private, work); struct net_device *ndev = priv->ndev; + int error; netif_tx_stop_all_queues(ndev); @@ -1452,15 +1453,36 @@ static void ravb_tx_timeout_work(struct work_struct *work) ravb_ptp_stop(ndev); /* Wait for DMA stopping */ - ravb_stop_dma(ndev); + if (ravb_stop_dma(ndev)) { + /* If ravb_stop_dma() fails, the hardware is still operating + * for TX and/or RX. So, this should not call the following + * functions because ravb_dmac_init() is possible to fail too. + * Also, this should not retry ravb_stop_dma() again and again + * here because it's possible to wait forever. So, this just + * re-enables the TX and RX and skip the following + * re-initialization procedure. + */ + ravb_rcv_snd_enable(ndev); + goto out; + } ravb_ring_free(ndev, RAVB_BE); ravb_ring_free(ndev, RAVB_NC); /* Device init */ - ravb_dmac_init(ndev); + error = ravb_dmac_init(ndev); + if (error) { + /* If ravb_dmac_init() fails, descriptors are freed. So, this + * should return here to avoid re-enabling the TX and RX in + * ravb_emac_init(). + */ + netdev_err(ndev, "%s: ravb_dmac_init() failed, error %d\n", + __func__, error); + return; + } ravb_emac_init(ndev); +out: /* Initialise PTP Clock driver */ if (priv->chip_id == RCAR_GEN2) ravb_ptp_init(ndev, priv->pdev); |