When enabling net console and console multiplexing, a boot crash was observed using mtk_eth driver with stdin/stdout set to "serial,nc" in persistent environment:

CPU: MediaTek MT7981 Model: OpenWrt One DRAM: 1 GiB Core: 35 devices, 15 uclasses, devicetree: separate spi-nand: spi_nand spi_nand@0: Winbond SPI NAND was found. spi-nand: spi_nand spi_nand@0: 128 MiB, block size: 128 KiB, page size: 2048, OOB size: 64 Loading Environment from UBI... SF: Detected w25q128 with page size 256 Bytes, erase size 4 KiB, total 16 MiB mtd: partition "ubi" extends beyond the end of device "spi-nand0" -- size truncated to 0x7f00000 Read 126976 bytes from volume ubootenv to 000000007f7bf0c0 Read 126976 bytes from volume ubootenv2 to 000000007f7de100 OK "Synchronous Abort" handler, esr 0x96000004, far 0xeafffffeea000018 elr: 0000000041e63cd4 lr : 0000000041e1b844 (reloc) elr: 000000007ff9ecd4 lr : 000000007ff56844 x0 : eafffffeea000018 x1 : 000000007fb552e0 x2 : 00000000000000fe x3 : 0000000000000000

The cause is that "serial,nc" forced the console subsystem to initialize the ethernet driver before ethernet subsystem initialization (console_init_r() is called before initr_net()).

During the mtk_eth driver initialization, mdio_register() will be called, and miiphy_get_dev_by_name() will then be called.

The miiphy_get_dev_by_name() will check the list "mii_devs" to see if the passed device name exists. However the mii_devs is defined without initialization:

static struct list_head mii_devs;

and the actual initialization is done in the following chain: initr_net -> eth_initialize -> eth_common_init -> miiphy_init Since initr_net() hasn't be called, iterating over the mii_devs will access to physical address 0 (mii_devs.next == NULL) and will cause the crash.

The fix is to define mii_devs using:

static LIST_HEAD(mii_devs);

As the "current_mii" is defined as a static variable, it will always be NULL in board_r stage and initializing it will NULL is unnecessary. So the entire miiphy_init() can be remove.

Signed-off-by: Weijie Gao hackpascal@gmail.com --- common/miiphyutil.c | 12 +----------- include/miiphy.h | 2 -- net/eth_common.c | 5 ----- 3 files changed, 1 insertion(+), 18 deletions(-)

diff --git a/common/miiphyutil.c b/common/miiphyutil.c index 9b8744e5d8..6169ea884a 100644 --- a/common/miiphyutil.c +++ b/common/miiphyutil.c @@ -30,7 +30,7 @@ #define debug(fmt, args...) #endif /* MII_DEBUG */

-static struct list_head mii_devs; +static LIST_HEAD(mii_devs); static struct mii_dev *current_mii;

/* @@ -55,16 +55,6 @@ struct mii_dev *miiphy_get_dev_by_name(const char *devname) return NULL; }

-/***************************************************************************** - * - * Initialize global data. Need to be called before any other miiphy routine. - */ -void miiphy_init(void) -{ - INIT_LIST_HEAD(&mii_devs); - current_mii = NULL; -} - struct mii_dev *mdio_alloc(void) { struct mii_dev *bus; diff --git a/include/miiphy.h b/include/miiphy.h index 5abffd8fb6..8e4b58c734 100644 --- a/include/miiphy.h +++ b/include/miiphy.h @@ -33,8 +33,6 @@ int miiphy_is_1000base_x(const char *devname, unsigned char addr); int miiphy_link(const char *devname, unsigned char addr); #endif

-void miiphy_init(void); - int miiphy_set_current_dev(const char *devname); const char *miiphy_get_current_dev(void); struct mii_dev *mdio_get_current_dev(void); diff --git a/net/eth_common.c b/net/eth_common.c index 89b5bb3718..ba57d836b0 100644 --- a/net/eth_common.c +++ b/net/eth_common.c @@ -31,11 +31,6 @@ int eth_env_set_enetaddr_by_index(const char *base_name, int index, void eth_common_init(void) { bootstage_mark(BOOTSTAGE_ID_NET_ETH_START); -#if CONFIG_IS_ENABLED(ETH) -#if defined(CONFIG_MII) || defined(CONFIG_CMD_MII) || defined(CONFIG_PHYLIB) - miiphy_init(); -#endif -#endif }

int eth_mac_skip(int index)