From 55cef88bbf12f3bfbe5c2379a8868a034707e755 Mon Sep 17 00:00:00 2001 From: Yoshitaka Ikeda Date: Thu, 15 Jul 2021 16:21:32 +0000 Subject: [PATCH] spi: spi-cadence-quadspi: Fix division by zero warning Fix below division by zero warning: - Added an if statement because buswidth can be zero, resulting in division by zero. - The modified code was based on another driver (atmel-quadspi). [ 0.795337] Division by zero in kernel. : [ 0.834051] [<807fd40c>] (__div0) from [<804e1acc>] (Ldiv0+0x8/0x10) [ 0.839097] [<805f0710>] (cqspi_exec_mem_op) from [<805edb4c>] (spi_mem_exec_op+0x3b0/0x3f8) Fixes: 7512eaf54190 ("spi: cadence-quadspi: Fix dummy cycle calculation when buswidth > 1") Signed-off-by: Yoshitaka Ikeda Link: https://lore.kernel.org/r/ed989af6-da88-4e0b-9ed8-126db6cad2e4@nskint.co.jp Signed-off-by: Mark Brown --- drivers/spi/spi-cadence-quadspi.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 7a00346..13d1f0c 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -307,11 +307,13 @@ static unsigned int cqspi_calc_rdreg(struct cqspi_flash_pdata *f_pdata) static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op, bool dtr) { - unsigned int dummy_clk; + unsigned int dummy_clk = 0; - dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth); - if (dtr) - dummy_clk /= 2; + if (op->dummy.buswidth && op->dummy.nbytes) { + dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth); + if (dtr) + dummy_clk /= 2; + } return dummy_clk; } -- 2.7.4