Currently barebox will try to talk to the phy over mdio, even if the parent is a fixed-link. This will result in the following stacktrace: barebox@Linux Automation Test Automation Controller (TAC):/ dhcp unable to handle NULL pointer dereference at address 0x00000130 pc : [<dfc01800>] lr : [<dfc0f963>] sp : dffefd40 ip : 004c4b40 fp : d00286e0 r10: cf25cc4e r9 : 00000000 r8 : 05f5e100 r7 : 00000130 r6 : 00000000 r5 : 00000000 r4 : 00000130 r3 : 00000109 r2 : 00000000 r1 : 00000000 r0 : 00000130 Flags: nZCv IRQs off FIQs off Mode SVC_32 WARNING: [<dfc01800>] (slice_acquire+0xc/0x28) from [<dfc0f963>] (mdiobus_read+0x13/0x28) WARNING: [<dfc0f963>] (mdiobus_read+0x13/0x28) from [<dfc10685>] (eqos_start+0x85/0x32c) WARNING: [<dfc10685>] (eqos_start+0x85/0x32c) from [<dfc3cdf1>] (eth_open+0xd/0x24) WARNING: [<dfc3cdf1>] (eth_open+0xd/0x24) from [<dfc3e391>] (dhcp+0xb/0x3a) WARNING: [<dfc3e391>] (dhcp+0xb/0x3a) from [<dfc30fab>] (do_dhcp+0xfb/0x114) WARNING: [<dfc30fab>] (do_dhcp+0xfb/0x114) from [<dfc0490f>] (execute_command+0x23/0x4c) WARNING: [<dfc0490f>] (execute_command+0x23/0x4c) from [<dfc0a127>] (run_list_real+0x5bf/0x638) WARNING: [<dfc0a127>] (run_list_real+0x5bf/0x638) from [<dfc09a2b>] (parse_stream_outer+0xc7/0x154) WARNING: [<dfc09a2b>] (parse_stream_outer+0xc7/0x154) from [<dfc0a383>] (run_shell+0x3f/0x6c) WARNING: [<dfc0a383>] (run_shell+0x3f/0x6c) from [<dfc010b9>] (run_init+0x191/0x200) WARNING: [<dfc010b9>] (run_init+0x191/0x200) from [<dfc01153>] (start_barebox+0x2b/0x6c) WARNING: [<dfc01153>] (start_barebox+0x2b/0x6c) from [<dfc4be6d>] (barebox_non_pbl_start+0x121/0x164) WARNING: [<dfc4be6d>] (barebox_non_pbl_start+0x121/0x164) from [<dfc00005>] (__bare_init_start+0x1/0xc) WARNING: [<dfc4da7d>] (unwind_backtrace+0x1/0x78) from [<dfc01461>] (panic+0x1d/0x34) WARNING: [<dfc01461>] (panic+0x1d/0x34) from [<dfc4b6a3>] (do_exception+0xf/0x14) WARNING: [<dfc4b6a3>] (do_exception+0xf/0x14) from [<dfc4b711>] (do_data_abort+0x21/0x34) WARNING: [<dfc4b711>] (do_data_abort+0x21/0x34) from [<dfc4b454>] (do_abort_6+0x48/0x54) Simply return with 0 if bus is zero which indicates that the phy is connected to a fixed link. Signed-off-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx> --- drivers/net/designware_eqos.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/net/designware_eqos.c b/drivers/net/designware_eqos.c index f83ec12714..f83e5d6d9b 100644 --- a/drivers/net/designware_eqos.c +++ b/drivers/net/designware_eqos.c @@ -362,6 +362,10 @@ static int phy_resume(struct phy_device *phydev) { int bmcr; + // Bus will be NULL if a fixed-link is used. + if (!phydev->bus) + return 0; + bmcr = phy_read(phydev, MII_BMCR); if (bmcr < 0) return bmcr; -- 2.32.0 _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox