On 2018-10-22 15:17, Sean Young wrote:
On Mon, Oct 22, 2018 at 01:28:42PM +0100, Sean Young wrote:
On Mon, Oct 22, 2018 at 12:30:29PM +0100, Hans Verkuil wrote:
On 10/22/2018 11:14 AM, Sean Young wrote:
Would you be able to test the following patch please?
Sean,
I think you should be able to test this with the vivid driver. Load the vivid driver, run:
cec-ctl --tv; cec-ctl -d1 --playback
Then:
cec-ctl -d1 -t0 --user-control-pressed ui-cmd=F5
Ah, thanks. That will help with testing/reproducing.
That said, I tried this, but it doesn't crash for me, but perhaps I need to run some RC command first...
Hmm I think those commands should be enough. It probably needs CONFIG_DEBUG_SPINLOCK to detect the uninitialized spinlock. I'm trying it now.
Yes, that turned out to work. With CONFIG_DEBUG_SPINLOCK on, it goes bang every time. With the patch, the problem goes away.
Without CONFIG_DEBUG_SPINLOCK we're going into undefined behaviour, so Torbjorn you're only seeing the oops occassionally (and which is why it has not been observed or reported before).
Thanks,
Sean
FYI i have tested this patch for a while now and have not seen any more kernel oops. So it appears to be working.