Re: [PATCH] coresight: fix the link between orphan connection and newly added device

[Mathieu Poirier]

On 13 January 2015 at 04:23, Kaixu Xia <xiakaixu@xxxxxxxxxx> wrote:
> 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 <xiakaixu@xxxxxxxxxx>
> ---
>  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
>

Applied, after annotating the commit log and fixing a checkpatch error.
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