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From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= <ilpo.jarvinen@linux.intel.com>
Date: Tue, 2 Apr 2024 14:38:48 +0300 (EEST)
To: Feng Chunguo <chunguo.feng@semidrive.com>
cc: Greg KH <gregkh@linuxfoundation.org>, 
    "fengchunguo@126.com" <fengchunguo@126.com>, 
    Andy Shevchenko <andriy.shevchenko@linux.intel.com>, 
    Jiri Slaby <jirislaby@kernel.org>, LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] tty: serial: fixed uart irq maybe cause irq storm
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On Mon, 1 Apr 2024, Feng Chunguo wrote:

> Hi Greg KH=EF=BC=8C
>=20
> Sent this path again.
>=20
> =C2=A0the irq should not be turned off here, what happens if some data co=
mes in while this
> function is running?=C2=A0 Will it be lost?
> --> lost=EF=BC=8Cnot receive other irq.
>=20
> =C2=A0When the uart was switching the baud rate from one to other,=C2=A0 =
this issue can be
> reproduced.


>> This feels wrong,
>> the irq should not be turned off here, what happens if some data comes i=
n while this
>> function is running? Will it be lost? thanks, greg k-h

Changing rate always risks losing what's currently on wire due to timing=20
related corruption, I don't think there there's a way around that IRQ=20
being enabled or not.


--=20
 i.
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