| From 733b92e36e8ed466fa8014818d2134b19b8ca2af Mon Sep 17 00:00:00 2001 |
| From: Martin Sperl <kernel@martin.sperl.org> |
| Date: Sat, 30 Mar 2019 09:30:59 +0000 |
| Subject: spi: bcm2835aux: remove dangerous uncontrolled read of fifo |
| |
| [ 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> |
| --- |
| drivers/spi/spi-bcm2835aux.c | 7 ------- |
| 1 file changed, 7 deletions(-) |
| |
| diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c |
| index 5b2c2b2e13396..4d233356772aa 100644 |
| --- a/drivers/spi/spi-bcm2835aux.c |
| +++ b/drivers/spi/spi-bcm2835aux.c |
| @@ -197,13 +197,6 @@ 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) |
| -- |
| 2.20.1 |
| |
