Re: [PATCH] remoteproc: k3-r5: Fix driver shutdown

From: Beleswar Prasad Padhi
Date: Tue Aug 20 2024 - 05:31:23 EST


Hi Jan,

On 19-08-2024 22:17, Jan Kiszka wrote:
From: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>

When k3_r5_cluster_rproc_exit is run, core 1 is shutdown and removed
first. When core 0 should then be stopped before its removal, it will
find core1->rproc as NULL already and crashes. Happens on rmmod e.g.


Did you check this on top of -next-20240820 tag? There was a series[0] which was merged recently which fixed this condition. I don't see this issue when trying on top of -next-20240820 tag.
[0]: https://lore.kernel.org/all/20240808074127.2688131-1-b-padhi@xxxxxx/


Fixes: 3c8a9066d584 ("remoteproc: k3-r5: Do not allow core1 to power up before core0 via sysfs")
CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jan Kiszka <jan.kiszka@xxxxxxxxxxx>
---

There might be one more because I can still make this driver crash
after an operator error. Were error scenarios tested at all?


Can you point out what is this issue more specifically, and I can take this up then.


drivers/remoteproc/ti_k3_r5_remoteproc.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/remoteproc/ti_k3_r5_remoteproc.c b/drivers/remoteproc/ti_k3_r5_remoteproc.c
index eb09d2e9b32a..9ebd7a34e638 100644
--- a/drivers/remoteproc/ti_k3_r5_remoteproc.c
+++ b/drivers/remoteproc/ti_k3_r5_remoteproc.c
@@ -646,7 +646,8 @@ static int k3_r5_rproc_stop(struct rproc *rproc)
/* do not allow core 0 to stop before core 1 */
core1 = list_last_entry(&cluster->cores, struct k3_r5_core,
elem);
- if (core != core1 && core1->rproc->state != RPROC_OFFLINE) {
+ if (core != core1 && core1->rproc &&
+ core1->rproc->state != RPROC_OFFLINE) {
dev_err(dev, "%s: can not stop core 0 before core 1\n",
__func__);
ret = -EPERM;