From 1f15b5e8733115cee65342bcaafeaf0368809fae Mon Sep 17 00:00:00 2001 From: "Russell King (Oracle)" Date: Mon, 25 Apr 2022 22:28:02 +0100 Subject: [PATCH 10/13] net: dsa: mt753x: fix pcs conversion regression Daniel Golle reports that the conversion of mt753x to phylink PCS caused an oops as below. The problem is with the placement of the PCS initialisation, which occurs after mt7531_setup() has been called. However, burited in this function is a call to setup the CPU port, which requires the PCS structure to be already setup. Fix this by changing the initialisation order. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 Mem abort info: ESR = 0x96000005 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x05: level 1 translation fault Data abort info: ISV = 0, ISS = 0x00000005 CM = 0, WnR = 0 user pgtable: 4k pages, 39-bit VAs, pgdp=0000000046057000 [0000000000000020] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 Internal error: Oops: 96000005 [#1] SMP Modules linked in: CPU: 0 PID: 32 Comm: kworker/u4:1 Tainted: G S 5.18.0-rc3-next-20220422+ #0 Hardware name: Bananapi BPI-R64 (DT) Workqueue: events_unbound deferred_probe_work_func pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : mt7531_cpu_port_config+0xcc/0x1b0 lr : mt7531_cpu_port_config+0xc0/0x1b0 sp : ffffffc008d5b980 x29: ffffffc008d5b990 x28: ffffff80060562c8 x27: 00000000f805633b x26: ffffff80001a8880 x25: 00000000000009c4 x24: 0000000000000016 x23: ffffff8005eb6470 x22: 0000000000003600 x21: ffffff8006948080 x20: 0000000000000000 x19: 0000000000000006 x18: 0000000000000000 x17: 0000000000000001 x16: 0000000000000001 x15: 02963607fcee069e x14: 0000000000000000 x13: 0000000000000030 x12: 0101010101010101 x11: ffffffc037302000 x10: 0000000000000870 x9 : ffffffc008d5b800 x8 : ffffff800028f950 x7 : 0000000000000001 x6 : 00000000662b3000 x5 : 00000000000002f0 x4 : 0000000000000000 x3 : ffffff800028f080 x2 : 0000000000000000 x1 : ffffff800028f080 x0 : 0000000000000000 Call trace: mt7531_cpu_port_config+0xcc/0x1b0 mt753x_cpu_port_enable+0x24/0x1f0 mt7531_setup+0x49c/0x5c0 mt753x_setup+0x20/0x31c dsa_register_switch+0x8bc/0x1020 mt7530_probe+0x118/0x200 mdio_probe+0x30/0x64 really_probe.part.0+0x98/0x280 __driver_probe_device+0x94/0x140 driver_probe_device+0x40/0x114 __device_attach_driver+0xb0/0x10c bus_for_each_drv+0x64/0xa0 __device_attach+0xa8/0x16c device_initial_probe+0x10/0x20 bus_probe_device+0x94/0x9c deferred_probe_work_func+0x80/0xb4 process_one_work+0x200/0x3a0 worker_thread+0x260/0x4c0 kthread+0xd4/0xe0 ret_from_fork+0x10/0x20 Code: 9409e911 937b7e60 8b0002a0 f9405800 (f9401005) ---[ end trace 0000000000000000 ]--- Reported-by: Daniel Golle Tested-by: Daniel Golle Fixes: cbd1f243bc41 ("net: dsa: mt7530: partially convert to phylink_pcs") Signed-off-by: Russell King (Oracle) Reviewed-by: Florian Fainelli Link: https://lore.kernel.org/r/E1nj6FW-007WZB-5Y@rmk-PC.armlinux.org.uk Signed-off-by: Jakub Kicinski --- drivers/net/dsa/mt7530.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) --- a/drivers/net/dsa/mt7530.c +++ b/drivers/net/dsa/mt7530.c @@ -3056,9 +3056,16 @@ static int mt753x_setup(struct dsa_switch *ds) { struct mt7530_priv *priv = ds->priv; - int ret = priv->info->sw_setup(ds); - int i; + int i, ret; + /* Initialise the PCS devices */ + for (i = 0; i < priv->ds->num_ports; i++) { + priv->pcs[i].pcs.ops = priv->info->pcs_ops; + priv->pcs[i].priv = priv; + priv->pcs[i].port = i; + } + + ret = priv->info->sw_setup(ds); if (ret) return ret; @@ -3070,13 +3077,6 @@ mt753x_setup(struct dsa_switch *ds) if (ret && priv->irq) mt7530_free_irq_common(priv); - /* Initialise the PCS devices */ - for (i = 0; i < priv->ds->num_ports; i++) { - priv->pcs[i].pcs.ops = priv->info->pcs_ops; - priv->pcs[i].priv = priv; - priv->pcs[i].port = i; - } - return ret; }