Re: crash by cdc_acm driver in kernels 4.8-rc1/5

From: Wim Osterholt
Date: Wed Nov 16 2016 - 20:57:42 EST

On Wed, Nov 16, 2016 at 04:07:57PM +0100, Wim Osterholt wrote:
> A bit of patience please. Yesterday I hadn't the modem at hand.

Whell, I lost track of what happens where with which config file..
Confusion about the bug not appearing an too many configs with SMP set
where I'm sure the machine(s) crashed on it.

The intention was to now use just one machine, to avoid confusion.
This is not going to work, due to problems with my video card.
(Crashes when it writes text beyond framebuffer space?)
VGA mode keeps working now.. We'll see..

Okay, a virgin start then.
A new 4.8.8 downloaded. A config from 4.7.9. Make oldconfig.
Accept all defaults for the new options.
CONFIG_SMP was set. Made two kernels, with and without SMP set.
Both kernels behaved the same: an OOPS at cdc_acm loading.
Fortunately the bug is still there.
In this very config the SMP setting does not seem to matter.

Now a retry of 4.9-rc5. I take the config of 4.8.8 and accept
the default for the new options.
SMP set. No call trace appears.
For completeness I should also try with SMP unset. That is for tomorrow

BTW, your latest patch was not yet applied here. At work where I had no oops
today, it gave an output count from 0 to 41, looping (30-39) through 16
buffers. More tomorrow. Need urgent sleep now.

Regards, Wim.