spi: sn-f-ospi: Fix division by zero

[ Upstream commit 3588b1c0fde2f58d166e3f94a5a58d64b893526c ]

When there is no dummy cycle in the spi-nor commands, both dummy bus cycle
bytes and width are zero. Because of the cpu's warning when divided by
zero, the warning should be avoided. Return just zero to avoid such
calculations.

Fixes: 1b74dd64c861 ("spi: Add Socionext F_OSPI SPI flash controller driver")
Co-developed-by: Kohei Ito <ito.kohei@socionext.com>
Signed-off-by: Kohei Ito <ito.kohei@socionext.com>
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Link: https://patch.msgid.link/20250206085747.3834148-1-hayashi.kunihiko@socionext.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/spi/spi-sn-f-ospi.c b/drivers/spi/spi-sn-f-ospi.c
index a7c3b3923b4af7918ca84deedc6189fe20079c92..fd8c8eb37d01d69b93757179949070c231dcc368 100644 (file)
--- a/drivers/spi/spi-sn-f-ospi.c
+++ b/drivers/spi/spi-sn-f-ospi.c
@@ -116,6 +116,9 @@ struct f_ospi {
 
 static u32 f_ospi_get_dummy_cycle(const struct spi_mem_op *op)
 {
+       if (!op->dummy.nbytes)
+               return 0;
+
        return (op->dummy.nbytes * 8) / op->dummy.buswidth;
 }