From 0e85ee897858b1c7a5de53f496d016899d9639c5 Mon Sep 17 00:00:00 2001 From: Yoshitaka Ikeda Date: Fri, 16 Jul 2021 14:35:13 +0000 Subject: [PATCH] spi: spi-cadence-quadspi: Fix division by zero warning Fix below division by zero warning: - The reason for dividing by zero is because the dummy bus width is zero, but if the dummy n bytes is zero, it indicates that there is no data transfer, so we can just return zero without doing any calculations. [ 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 Reviewed-by: Pratyush Yadav Link: https://lore.kernel.org/r/92eea403-9b21-2488-9cc1-664bee760c5e@nskint.co.jp Signed-off-by: Mark Brown --- drivers/spi/spi-cadence-quadspi.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 7a00346ff9b9..d62d69dd72b9 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -309,6 +309,9 @@ static unsigned int cqspi_calc_dummy(const struct spi_mem_op *op, bool dtr) { unsigned int dummy_clk; + if (!op->dummy.nbytes) + return 0; + dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth); if (dtr) dummy_clk /= 2;