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Message-Id: <20200102220547.639847436@linuxfoundation.org>
Date: Thu, 2 Jan 2020 23:06:20 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Lukasz Majewski <lukma@...x.de>,
Mark Brown <broonie@...nel.org>,
kbuild test robot <lkp@...el.com>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.4 007/137] spi: Add call to spi_slave_abort() function when spidev driver is released
From: Lukasz Majewski <lukma@...x.de>
[ Upstream commit 9f918a728cf86b2757b6a7025e1f46824bfe3155 ]
This change is necessary for spidev devices (e.g. /dev/spidev3.0) working
in the slave mode (like NXP's dspi driver for Vybrid SoC).
When SPI HW works in this mode - the master is responsible for providing
CS and CLK signals. However, when some fault happens - like for example
distortion on SPI lines - the SPI Linux driver needs a chance to recover
from this abnormal situation and prepare itself for next (correct)
transmission.
This change doesn't pose any threat on drivers working in master mode as
spi_slave_abort() function checks if SPI slave mode is supported.
Signed-off-by: Lukasz Majewski <lukma@...x.de>
Link: https://lore.kernel.org/r/20190924110547.14770-2-lukma@denx.de
Signed-off-by: Mark Brown <broonie@...nel.org>
Reported-by: kbuild test robot <lkp@...el.com>
Link: https://lore.kernel.org/r/20190925091143.15468-2-lukma@denx.de
Signed-off-by: Mark Brown <broonie@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
drivers/spi/spidev.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/spi/spidev.c b/drivers/spi/spidev.c
index c5f1045561ac..3709088d4d24 100644
--- a/drivers/spi/spidev.c
+++ b/drivers/spi/spidev.c
@@ -662,6 +662,9 @@ static int spidev_release(struct inode *inode, struct file *filp)
if (dofree)
kfree(spidev);
}
+#ifdef CONFIG_SPI_SLAVE
+ spi_slave_abort(spidev->spi);
+#endif
mutex_unlock(&device_list_lock);
return 0;
--
2.20.1
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