spi: bcm2835aux: remove dangerous uncontrolled read of fifo

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: 1ea29b39f4 ("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>
This commit is contained in:
Martin Sperl 2019-03-30 09:30:59 +00:00 committed by Mark Brown
parent 7188a6f0ee
commit c7de8500fd
No known key found for this signature in database
GPG key ID: 24D68B725D5487D0

View file

@ -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)