From 2cbd27267ffe020af1442b95ec57f59a157ba85c Mon Sep 17 00:00:00 2001 From: Kamal Dasu Date: Thu, 27 Jan 2022 13:53:59 -0500 Subject: [PATCH] spi: bcm-qspi: check for valid cs before applying chip select Apply only valid chip select value. This change fixes case where chip select is set to initial value of '-1' during probe and PM supend and subsequent resume can try to use the value with undefined behaviour. Also in case where gpio based chip select, the check in bcm_qspi_chip_select() shall prevent undefined behaviour on resume. Fixes: fa236a7ef240 ("spi: bcm-qspi: Add Broadcom MSPI driver") Signed-off-by: Kamal Dasu Acked-by: Florian Fainelli Link: https://lore.kernel.org/r/20220127185359.27322-1-kdasu.kdev@gmail.com Signed-off-by: Mark Brown --- drivers/spi/spi-bcm-qspi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c index c9a769b..86c7621 100644 --- a/drivers/spi/spi-bcm-qspi.c +++ b/drivers/spi/spi-bcm-qspi.c @@ -585,7 +585,7 @@ static void bcm_qspi_chip_select(struct bcm_qspi *qspi, int cs) u32 rd = 0; u32 wr = 0; - if (qspi->base[CHIP_SELECT]) { + if (cs >= 0 && qspi->base[CHIP_SELECT]) { rd = bcm_qspi_read(qspi, CHIP_SELECT, 0); wr = (rd & ~0xff) | (1 << cs); if (rd == wr) -- 2.7.4