net: ti: am65-cpsw-nuss: Fix crash when changing number of TX queues

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@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/ti/am65-cpsw-nuss.c b/drivers/net/ethernet/ti/am65-cpsw-nuss.c
index 6a67b02..718539c 100644 (file)
--- 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)