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authorYoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>2020-07-21 15:23:12 +0900
committerDavid S. Miller <davem@davemloft.net>2020-07-21 15:34:07 -0700
commit015c5d5e6aa3523c758a70eb87b291cece2dbbb4 (patch)
tree4e7fca94fa67c33bd4f7198030e0ab11abc56f3a /drivers/net/ethernet/renesas
parentca673235523019ac58dda5287d9c819e19702860 (diff)
net: ethernet: ravb: exit if re-initialization fails in tx timeout
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>
Diffstat (limited to 'drivers/net/ethernet/renesas')
-rw-r--r--drivers/net/ethernet/renesas/ravb_main.c26
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 a442bcf64b9c..99f7aae102ce 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -1450,6 +1450,7 @@ 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);
@@ -1458,15 +1459,36 @@ 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);