When found a component that has one orphan connection, we should validate if it match the newly added device. If it does not match, this component still has an orphan connection(still_orphan = true). The process should be like this. The original logic maybe cause path building failed.
The tested result as follows. pre: /sys/bus/coresight/devices # echo 1 > e3c42000.etb/enable_sink /sys/bus/coresight/devices # echo 1 > e3c7c000.ptm/enable_source [ 15.527692] Unable to handle kernel NULL pointer dereference at virtual address 00000124 [ 15.555142] pgd = c2294000 [ 15.564226] [00000124] *pgd=3d393831, *pte=00000000, *ppte=00000000 [ 15.585391] Internal error: Oops: 817 [#1] PREEMPT SMP ARM [ 15.603807] CPU: 0 PID: 144 Comm: sh Not tainted 3.17.0-rc1-12634-g1222fe0-dirty #3 [ 15.629490] task: ed3803c0 ti: c213a000 task.ti: c213a000 [ 15.647627] PC is at coresight_build_paths+0x1c/0x314 [ 15.664579] LR is at coresight_build_paths+0x6c/0x314 [ 15.681526] pc : [<c02da20c>] lr : [<c02da25c>] psr: 20000013 [ 15.681526] sp : c213be88 ip : c02da800 fp : 00000000 [ 15.720023] r10: 00000002 r9 : ed13250c r8 : 00000001 [ 15.737549] r7 : c213bee8 r6 : ffffffea r5 : 00000000 r4 : 00000124 [ 15.759446] r3 : ed216f24 r2 : 00000001 r1 : c213bee8 r0 : 00000000 [ 15.781346] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user post: /sys/bus/coresight/devices # echo 1 > e3c42000.etb/enable_sink /sys/bus/coresight/devices # echo 1 > e3c7c000.ptm/enable_source [ 59.934255] coresight-etb10 e3c42000.etb: ETB enabled [ 59.951317] coresight-replicator replicator0: REPLICATOR enabled [ 59.971581] coresight-funnel e3c41000.funnel: FUNNEL inport 0 enabled [ 59.993334] coresight-etm3x e3c7c000.ptm: ETM tracing enabled Signed-off-by: Kaixu Xia <[email protected]> --- drivers/coresight/coresight.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/coresight/coresight.c b/drivers/coresight/coresight.c index 6e0181f..11968b7 100644 --- a/drivers/coresight/coresight.c +++ b/drivers/coresight/coresight.c @@ -504,11 +504,12 @@ static int coresight_orphan_match(struct device *dev, void *data) /* We have found at least one orphan connection */ if (conn->child_dev == NULL) { /* Does it match this newly added device? */ - if (!strcmp(dev_name(&csdev->dev), conn->child_name)) + if (!strcmp(dev_name(&csdev->dev), conn->child_name)) { conn->child_dev = csdev; - } else { - /* Too bad, this component still has an orphan */ - still_orphan = true; + } else { + /* Too bad, this component still has an orphan */ + still_orphan = true; + } } } -- 1.8.5.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
