| From 2cbd27267ffe020af1442b95ec57f59a157ba85c Mon Sep 17 00:00:00 2001 |
| From: Kamal Dasu <kdasu.kdev@gmail.com> |
| Date: Thu, 27 Jan 2022 13:53:59 -0500 |
| Subject: spi: bcm-qspi: check for valid cs before applying chip select |
| |
| From: Kamal Dasu <kdasu.kdev@gmail.com> |
| |
| commit 2cbd27267ffe020af1442b95ec57f59a157ba85c upstream. |
| |
| 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 <kdasu.kdev@gmail.com> |
| Acked-by: Florian Fainelli <f.fainelli@gmail.com> |
| Link: https://lore.kernel.org/r/20220127185359.27322-1-kdasu.kdev@gmail.com |
| Signed-off-by: Mark Brown <broonie@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/spi/spi-bcm-qspi.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/spi/spi-bcm-qspi.c |
| +++ b/drivers/spi/spi-bcm-qspi.c |
| @@ -551,7 +551,7 @@ static void bcm_qspi_chip_select(struct |
| 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) |
