coresight: fix the link between orphan connection and newly added device

When founding a component that has orphan connections, we should
validate if it match the newly added device. If it does not match,
only then should the @still_orphan flag should be set.

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 <xiakaixu@huawei.com>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/coresight/coresight.c b/drivers/coresight/coresight.c
index 6e0181f844258113358cbfc7988cdabd1bb58774..d6052e2cd6a70bb72ec493695743f279e705f40f 100644 (file)
--- 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 {
+                               /* This component still has an orphan */
+                               still_orphan = true;
+                       }
                }
        }