Re: [PATCH 1/2] serial: imx: Introduce timeout when waiting on transmitter empty

From: Esben Haabendal <esben@geanix.com>
To: Fabio Estevam <festevam@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	 Jiri Slaby <jirislaby@kernel.org>,
	 Shawn Guo <shawnguo@kernel.org>,
	 Sascha Hauer <s.hauer@pengutronix.de>,
	 Pengutronix Kernel Team <kernel@pengutronix.de>,
	 Marc Kleine-Budde <mkl@pengutronix.de>,
	linux-kernel@vger.kernel.org,  linux-serial@vger.kernel.org,
	imx@lists.linux.dev,  linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/2] serial: imx: Introduce timeout when waiting on transmitter empty
Date: Mon, 08 Apr 2024 10:56:16 +0200	[thread overview]
Message-ID: <87ttkckzbj.fsf@geanix.com> (raw)
In-Reply-To: <CAOMZO5Axz7un+9H2uEoQtE0=pYNC0hEyZiNobrSi2m0ajj8N+g@mail.gmail.com> (Fabio Estevam's message of "Fri, 5 Apr 2024 14:38:48 -0300")

Fabio Estevam <festevam@gmail.com> writes:

> On Fri, Apr 5, 2024 at 6:25 AM Esben Haabendal <esben@geanix.com> wrote:
>>
>> By waiting at most 1 second for USR2_TXDC to be set, we avoid a potentital
>
> s/potentital/potential

Thanks, fixing.

> Could you elaborate on this deadlock? Have you seen it in practice?

I cannot say for sure if I have seen it. But in some cases, that is
exactly what you would see. Nothing.

If it would occur during shutdown, the console would simply stop/block,
and you would see nothing.

> Should a Fixes tag be added?

Which commit should I add to that tag? The polling without timeout dates
back to at least 2.6.12-rc2.

/Esben