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List:       linux-serial
Subject:    Re: Regression since 4a96895f74c9633b51427fd080ab70fa62b65bc4
From:       Nuno_Gonçalves <nunojpg () gmail ! com>
Date:       2019-09-29 6:46:47
Message-ID: CAEXMXLSty8v1K_yaxoAnoMEny=XYn2ngUdCPi_0uTqy5NTViAQ () mail ! gmail ! com
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I have since found that I am affected by two apparently different
regressions since 5.3.

4a96895f74c9633b51427fd080ab70fa62b65bc4 is only confirmed to affect
me on a omap8250 where the issue is that there are a few char errors
every few seconds. I can't confirm if chars are added, removed or
changed, for now I only can confirm my state machine looses tracking.

I will make a separate report from the problem identified on sunxi.

On Sat, Sep 28, 2019 at 7:59 AM Nuno Gon=C3=A7alves <nunojpg@gmail.com> wro=
te:
>
> On 32 bit arm platforms (am335x and sunxi) I get unexpected bytes on
> serial ports after this commit.
>
> I use CTS (so: for input flow control).
>
> I've observed two different issues, one where I get just a few missed
> or added bytes about once a minute, and another where I get totally
> unexpected chars until I reopen the port.
>
> I will have a hard time to analyse and give a better description of
> how exactly the port is failing, so maybe you have a idea of what is
> the issue with this patch.
>
> I've reverted this on top of 5.3.1 and consistently got the issue fixed.
>
> Thanks,
> Nuno
>
> commit 4a96895f74c9633b51427fd080ab70fa62b65bc4
> Author: Yegor Yefremov <yegorslists@googlemail.com>
> Date:   Thu Jun 20 08:24:20 2019 +0200
>
>     tty/serial/8250: use mctrl_gpio helpers
>
>     This patch permits the usage for GPIOs to control
>     the CTS/RTS/DTR/DSR/DCD/RI signals.
>
>     Changed by Stefan:
>     Only call mctrl_gpio_init(), if the device has no ACPI companion devi=
ce
>     to not break existing ACPI based systems. Also only use the mctrl_gpi=
o_
>     functions when "gpios" is available.
>
>     Use MSR / MCR <-> TIOCM wrapper functions.
>
>     Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
>     Signed-off-by: Stefan Roese <sr@denx.de>
>     Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>     Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
>     Tested-by: Yegor Yefremov <yegorslists@googlemail.com>
>     Cc: Mika Westerberg <mika.westerberg@linux.intel.com>
>     Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
>     Cc: Giulio Benetti <giulio.benetti@micronovasrl.com>
>     Cc: Yegor Yefremov <yegorslists@googlemail.com>
>     Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>     Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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