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From: Douglas Anderson <dianders@chromium.org>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Jiri Slaby <jirislaby@kernel.org>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	John Ogness <john.ogness@linutronix.de>,
	Tony Lindgren <tony@atomide.com>,
	linux-arm-msm@vger.kernel.org,
	Johan Hovold <johan+linaro@kernel.org>,
	=?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <u.kleine-koenig@pengutronix.de>,
	Yicong Yang <yangyicong@hisilicon.com>,
	Douglas Anderson <dianders@chromium.org>,
	Guanbing Huang <albanhuang@tencent.com>,
	James Clark <james.clark@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Vijaya Krishna Nivarthi <quic_vnivarth@quicinc.com>,
	linux-kernel@vger.kernel.org,
	linux-serial@vger.kernel.org
Subject: [PATCH 0/2] serial: Fix problems when serial transfer is happening at suspend time
Date: Thu, 23 May 2024 16:22:11 -0700
Message-ID: <20240523232216.3148367-1-dianders@chromium.org>
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This is a set of two patches that fix problems related to suspending
while a serial transfer is going on. The two patches are independent
from each other and can land in any order. The only thing tying them
together is that I used the same test to reproduce both of them.
Specifically, I could reproduce my problemes by logging in via an
agetty on the debug serial port (which was _not_ used for kernel
console) and running:
  cat /var/log/messages
..and then (via an SSH session) forcing a few suspend/resume cycles.

The first patch solves a problem that is probably more major. It was
introduced recently and has even shown up in stable trees.
Suspend/resume testing in ChromeOS test labs are hitting the problem
fixed by this patch. The fix hasn't been tested in labs, but when I
reproduced the problem locally I could see that the fix worked. IMO it
should land ASAP.

The second patch fixes an ancient problem that I only found because I
was trying to reproduce the first problem. Given how long it's been
around it's probably not urgent but it would be nice to get fixed.


Douglas Anderson (2):
  serial: port: Don't block system suspend even if bytes are left to
    xmit
  serial: qcom-geni: Fix qcom_geni_serial_stop_tx_fifo() while xfer

 drivers/tty/serial/qcom_geni_serial.c | 45 +++++++++++++++++++++++++--
 drivers/tty/serial/serial_port.c      | 10 ++++++
 2 files changed, 52 insertions(+), 3 deletions(-)

-- 
2.45.1.288.g0e0cd299f1-goog