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spi: bcm2835aux: remove dangerous uncontrolled read of fifo

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[ Upstream commit c7de8500fd8ecbb544846dd5f11dca578c3777e1 ]

This read of the fifo is a potential candidate for a race condition
as the spi transfer is not necessarily finished and so can lead to
an early read of the fifo that still misses data.

So it has been removed.

Fixes: 1ea29b39f4c812ec ("spi: bcm2835aux: add bcm2835 auxiliary spi device...")
Suggested-by: Hubert Denkmair <h.denkmair@intence.de>
Signed-off-by: Martin Sperl <kernel@martin.sperl.org>
Acked-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Martin Sperl 2019-03-30 09:30:59 +00:00 committed by Greg Kroah-Hartman
parent a4a9ee7903
commit fe49c3de73
1 changed files with 0 additions and 7 deletions
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7
drivers/spi/spi-bcm2835aux.c
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@ -194,13 +194,6 @@ static void bcm2835aux_spi_transfer_helper(struct bcm2835aux_spi *bs)
BCM2835_AUX_SPI_STAT_TX_FULL))) {
bcm2835aux_wr_fifo(bs);
}
/* and check if we have reached "done" */
while (bs->rx_len &&
(!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT) &
BCM2835_AUX_SPI_STAT_BUSY))) {
bcm2835aux_rd_fifo(bs);
}
}
static irqreturn_t bcm2835aux_spi_interrupt(int irq, void *dev_id)