Re: [PATCH v2 0/5] usb: gadget: u_serial: Fix and cleanup

[Ladislav Michl <ladis@linux-mips.org>]

On Sun, Jul 14, 2019 at 01:37:17PM +0200, Michał Mirosław wrote:
> On Sun, Jul 14, 2019 at 12:04:26PM +0200, Michał Mirosław wrote:
> > On Sat, Jul 13, 2019 at 11:08:53PM +0200, Ladislav Michl wrote:
> > > Following patchset makes console work (patch 1 and 4) for an AT91SAM9G20
> > > board connected to xhci_hcd and does some cleanup.
> > > Tested with "console=ttyS0,115200n8 console=ttyGS0" on kernel command line
> > > and following inittab:
> > > console::respawn:/sbin/getty -L 115200 ttyS0 vt100
> > > console::respawn:/sbin/getty -L 115200 ttyGS0 vt100
> > > 
> > > However there is an issue remaining:
> > > Disconnect triggers WARN_ON in gs_close:
> > [...]
> > 
> > Hi,
> > 
> > Can you try a patchset I sent some time ago [1] if it fixes your case?
> 
> You can pull it from branch usb-console on https://rere.qmqm.pl/git/linux
> (rebased on current usb-next tree).

Thank you! I has just in the middle of pulling patches from mail archive.

Your first two patches are definitely worth applying and I'll add my
Tested-by after more testing. 3/5 is unfortunately "I do not care" as
not having use case, 4/5 is something I do not see use case either, but
I'm fine with that, except for #ifdefs, but 5/5 should be solved the
other way around - just wait until everything is written out, of course
only if USB is connected. That's what serial consoles does and that's
what I expect from kernel console.

Your patch set does not attempt to solve tty write to unconnected USB
and WARN_ON on gs_close, so I'll wait for comments to those two issues
and redo fix on top of "reimplement console support" as getting rid of
the kthread is definitely superior to fixing it :)

Best regards,
	ladis