[PATCH 5.13 541/800] net: ti: am65-cpsw-nuss: Fix crash when changing number of TX queues

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 04:45:30 EST


From: Vignesh Raghavendra <vigneshr@xxxxxx>

[ Upstream commit ce8eb4c728ef40b554b4f3d8963f11ed44502e00 ]

When changing number of TX queues using ethtool:

# ethtool -L eth0 tx 1
[ 135.301047] Unable to handle kernel paging request at virtual address 00000000af5d0000
[...]
[ 135.525128] Call trace:
[ 135.525142] dma_release_from_dev_coherent+0x2c/0xb0
[ 135.525148] dma_free_attrs+0x54/0xe0
[ 135.525156] k3_cppi_desc_pool_destroy+0x50/0xa0
[ 135.525164] am65_cpsw_nuss_remove_tx_chns+0x88/0xdc
[ 135.525171] am65_cpsw_set_channels+0x3c/0x70
[...]

This is because k3_cppi_desc_pool_destroy() which is called after
k3_udma_glue_release_tx_chn() in am65_cpsw_nuss_remove_tx_chns()
references struct device that is unregistered at the end of
k3_udma_glue_release_tx_chn()

Therefore the right order is to call k3_cppi_desc_pool_destroy() and
destroy desc pool before calling k3_udma_glue_release_tx_chn().
Fix this throughout the driver.

Fixes: 93a76530316a ("net: ethernet: ti: introduce am65x/j721e gigabit eth subsystem driver")
Signed-off-by: Vignesh Raghavendra <vigneshr@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/net/ethernet/ti/am65-cpsw-nuss.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 6a67b026df0b..718539cdd2f2 100644
--- a/drivers/net/ethernet/ti/am65-cpsw-nuss.c
+++ b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
@@ -1506,12 +1506,12 @@ static void am65_cpsw_nuss_free_tx_chns(void *data)
for (i = 0; i < common->tx_ch_num; i++) {
struct am65_cpsw_tx_chn *tx_chn = &common->tx_chns[i];

- if (!IS_ERR_OR_NULL(tx_chn->tx_chn))
- k3_udma_glue_release_tx_chn(tx_chn->tx_chn);
-
if (!IS_ERR_OR_NULL(tx_chn->desc_pool))
k3_cppi_desc_pool_destroy(tx_chn->desc_pool);

+ if (!IS_ERR_OR_NULL(tx_chn->tx_chn))
+ k3_udma_glue_release_tx_chn(tx_chn->tx_chn);
+
memset(tx_chn, 0, sizeof(*tx_chn));
}
}
@@ -1531,12 +1531,12 @@ void am65_cpsw_nuss_remove_tx_chns(struct am65_cpsw_common *common)

netif_napi_del(&tx_chn->napi_tx);

- if (!IS_ERR_OR_NULL(tx_chn->tx_chn))
- k3_udma_glue_release_tx_chn(tx_chn->tx_chn);
-
if (!IS_ERR_OR_NULL(tx_chn->desc_pool))
k3_cppi_desc_pool_destroy(tx_chn->desc_pool);

+ if (!IS_ERR_OR_NULL(tx_chn->tx_chn))
+ k3_udma_glue_release_tx_chn(tx_chn->tx_chn);
+
memset(tx_chn, 0, sizeof(*tx_chn));
}
}
@@ -1624,11 +1624,11 @@ static void am65_cpsw_nuss_free_rx_chns(void *data)

rx_chn = &common->rx_chns;

- if (!IS_ERR_OR_NULL(rx_chn->rx_chn))
- k3_udma_glue_release_rx_chn(rx_chn->rx_chn);
-
if (!IS_ERR_OR_NULL(rx_chn->desc_pool))
k3_cppi_desc_pool_destroy(rx_chn->desc_pool);
+
+ if (!IS_ERR_OR_NULL(rx_chn->rx_chn))
+ k3_udma_glue_release_rx_chn(rx_chn->rx_chn);
}

static int am65_cpsw_nuss_init_rx_chns(struct am65_cpsw_common *common)
--
2.30.2