From 9600bdd6924afecf1104ecc5f83e068f585c856f Mon Sep 17 00:00:00 2001 From: Jon Lin Date: Thu, 23 Jul 2020 08:43:56 +0800 Subject: [PATCH] spi: rockchip: Fix error in SPI slave pio read [ 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 Tested-by: Emil Renner Berthing Reviewed-by: Heiko Stuebner Reviewed-by: Emil Renner Berthing Link: https://lore.kernel.org/r/20200723004356.6390-3-jon.lin@rock-chips.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- 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 2cc6d9951b52..008b64f4e031 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