From: Akash Asthana <akashast@codeaurora.org>
To: Douglas Anderson <dianders@chromium.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>,
robdclark@chromium.org,
Nathan Chancellor <natechancellor@gmail.com>,
jwerner@chromium.org, Andy Gross <agross@kernel.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Jiri Slaby <jirislaby@kernel.org>,
linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-serial@vger.kernel.org
Subject: Re: [PATCH] tty: serial: qcom_geni_serial: 115.2 is a better console default than 9600
Date: Mon, 14 Sep 2020 15:29:25 +0530 [thread overview]
Message-ID: <981cfc91-035e-57cb-5972-e2a749adae98@codeaurora.org> (raw)
In-Reply-To: <20200911080054.1.I4c00b921c2f17b6988688046fa7be0f729f8d591@changeid>
On 9/11/2020 8:30 PM, Douglas Anderson wrote:
> Commit c5cbc78acf69 ("tty: serial: qcom_geni_serial: Initialize baud
> in qcom_geni_console_setup") fixed a bug by initting a variable that
> was used in some cases without initialization. However, the "default"
> baud rate picked by that CL was probably not the best choice. The
> chances that anyone out there is trying to run a system with kernel
> messages piped out over a 9600 baud serial port is just about nil.
> Console messages are printed in a blocking manner. At 9600 baud we
> print about 1 character per millisecond which means that printing a
> 40-byte message to the console will take ~40 ms. While it would
> probably work, it's going to make boot _very_ slow and probably cause
> the occasional timeout here and there in drivers (heck, even at 115200
> console delays can wreck havoc).
>
> This has already bit at least two people that I'm aware of that tried
> to enable serial console by just adding "console=ttyMSM0" (instead of
> "console=ttyMSM0,115200n8") to the command line, so it seems like it'd
> be nice to fix.
>
> Let's switch the default to 115200.
Reviewed-by: Akash Asthana <akashast@codeaurora.org>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
>
>
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,\na Linux Foundation Collaborative Project
next prev parent reply other threads:[~2020-09-14 10:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-11 15:00 [PATCH] tty: serial: qcom_geni_serial: 115.2 is a better console default than 9600 Douglas Anderson
2020-09-11 15:55 ` Nathan Chancellor
2020-09-14 9:59 ` Akash Asthana [this message]
2020-09-14 15:39 ` Bjorn Andersson
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