| Message ID | 20210420164425.40287-2-andriy.shevchenko@linux.intel.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2,1/2] spi: Allow to have all native CSs in use along with GPIOs | expand |
diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 9c3730a9f7d5..01f95bee2ac8 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -2609,7 +2609,7 @@ static int spi_get_gpio_descs(struct spi_controller *ctlr) native_cs_mask |= BIT(i); } - ctlr->unused_native_cs = ffz(native_cs_mask); + ctlr->unused_native_cs = ffs(~native_cs_mask) - 1; if ((ctlr->flags & SPI_MASTER_GPIO_SS) && num_cs_gpios && ctlr->max_native_cs && ctlr->unused_native_cs >= ctlr->max_native_cs) {
ffz(), that has been used to count unused native CSs, might cause undefined behaviour when called against ~0U. To fix that, open code it with ffs(~value) - 1. Fixes: 7d93aecdb58d ("spi: Add generic support for unused native cs with cs-gpios") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- v2: decoded UB abbreviation (Mark) drivers/spi/spi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)