On Wed, 20 Dec 2023 17:40:42 +0200
Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> wrote:
> On Tue, Dec 19, 2023 at 12:18:46PM -0500, Hugo Villeneuve wrote:
> > From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
> >
> > If an error occurs during probing, the sc16is7xx_lines bitfield may be left
> > in a state that doesn't represent the correct state of lines allocation.
> >
> > For example, in a system with two SC16 devices, if an error occurs only
> > during probing of channel (port) B of the second device, sc16is7xx_lines
> > final state will be 00001011b instead of the expected 00000011b.
> >
> > This is caused in part because of the "i--" in the for/loop located in
> > the out_ports: error path.
> >
> > Fix this by checking the return value of uart_add_one_port() and set line
> > allocation bit only if this was successful. This allows the refactor of
> > the obfuscated for(i--...) loop in the error path, and properly call
> > uart_remove_one_port() only when needed, and properly unset line allocation
> > bits.
> >
> > Also use same mechanism in remove() when calling uart_remove_one_port().
>
> Yes, this seems to be the correct one to fix the problem described in
> the patch 1. I dunno why the patch 1 even exists.
Hi,
this will indeed fix the problem described in patch 1.
However, if I remove patch 1, and I simulate the same probe error as
described in patch 1, now we get stuck forever when trying to
remove the driver. This is something that I observed before and
that patch 1 also corrected.
The problem is caused in sc16is7xx_remove() when calling this function
kthread_flush_worker(&s->kworker);
I am not sure how best to handle that without patch 1.
Hugo Villeneuve
