From: Jon Lin jon.lin@rock-chips.com
[ Upstream commit 4294e4accf8d695ea5605f6b189008b692e3e82c ]
The RXFLR is possible larger than rx_left in Rockchip SPI, fix it.
Fixes: 01b59ce5dac8 ("spi: rockchip: use irq rather than polling") Signed-off-by: Jon Lin jon.lin@rock-chips.com Tested-by: Emil Renner Berthing kernel@esmil.dk Reviewed-by: Heiko Stuebner heiko@sntech.de Reviewed-by: Emil Renner Berthing kernel@esmil.dk Link: https://lore.kernel.org/r/20200723004356.6390-3-jon.lin@rock-chips.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-rockchip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c index 70ef63e0b6b8d..02e9205355910 100644 --- a/drivers/spi/spi-rockchip.c +++ b/drivers/spi/spi-rockchip.c @@ -286,7 +286,7 @@ static void rockchip_spi_pio_writer(struct rockchip_spi *rs) static void rockchip_spi_pio_reader(struct rockchip_spi *rs) { u32 words = readl_relaxed(rs->regs + ROCKCHIP_SPI_RXFLR); - u32 rx_left = rs->rx_left - words; + u32 rx_left = (rs->rx_left > words) ? rs->rx_left - words : 0;
/* the hardware doesn't allow us to change fifo threshold * level while spi is enabled, so instead make sure to leave