[PATCH 4.9 028/107] net: axienet: Fix double deregister of mdio
From: Greg Kroah-Hartman
Date: Mon Sep 03 2018 - 13:04:30 EST
4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
[ Upstream commit 03bc7cab7d7218088412a75e141696a89059ab00 ]
If the registration fails then mdio_unregister is called.
However at unbind the unregister ia attempted again resulting
in the below crash
[ 73.544038] kernel BUG at drivers/net/phy/mdio_bus.c:415!
[ 73.549362] Internal error: Oops - BUG: 0 [#1] SMP
[ 73.554127] Modules linked in:
[ 73.557168] CPU: 0 PID: 2249 Comm: sh Not tainted 4.14.0 #183
[ 73.562895] Hardware name: xlnx,zynqmp (DT)
[ 73.567062] task: ffffffc879e41180 task.stack: ffffff800cbe0000
[ 73.572973] PC is at mdiobus_unregister+0x84/0x88
[ 73.577656] LR is at axienet_mdio_teardown+0x18/0x30
[ 73.582601] pc : [<ffffff80085fa4cc>] lr : [<ffffff8008616858>]
pstate: 20000145
[ 73.589981] sp : ffffff800cbe3c30
[ 73.593277] x29: ffffff800cbe3c30 x28: ffffffc879e41180
[ 73.598573] x27: ffffff8008a21000 x26: 0000000000000040
[ 73.603868] x25: 0000000000000124 x24: ffffffc879efe920
[ 73.609164] x23: 0000000000000060 x22: ffffffc879e02000
[ 73.614459] x21: ffffffc879e02800 x20: ffffffc87b0b8870
[ 73.619754] x19: ffffffc879e02800 x18: 000000000000025d
[ 73.625050] x17: 0000007f9a719ad0 x16: ffffff8008195bd8
[ 73.630345] x15: 0000007f9a6b3d00 x14: 0000000000000010
[ 73.635640] x13: 74656e7265687465 x12: 0000000000000030
[ 73.640935] x11: 0000000000000030 x10: 0101010101010101
[ 73.646231] x9 : 241f394f42533300 x8 : ffffffc8799f6e98
[ 73.651526] x7 : ffffffc8799f6f18 x6 : ffffffc87b0ba318
[ 73.656822] x5 : ffffffc87b0ba498 x4 : 0000000000000000
[ 73.662117] x3 : 0000000000000000 x2 : 0000000000000008
[ 73.667412] x1 : 0000000000000004 x0 : ffffffc8799f4000
[ 73.672708] Process sh (pid: 2249, stack limit = 0xffffff800cbe0000)
Fix the same by making the bus NULL on unregister.
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c | 1 +
1 file changed, 1 insertion(+)
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_mdio.c
@@ -217,6 +217,7 @@ issue:
ret = of_mdiobus_register(bus, np1);
if (ret) {
mdiobus_free(bus);
+ lp->mii_bus = NULL;
return ret;
}
return 0;