| From 8e7f9650f5d883bca7b0239529c1b704673abd38 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 15 Jul 2021 16:21:32 +0000 |
| Subject: spi: spi-cadence-quadspi: Fix division by zero warning |
| |
| From: Yoshitaka Ikeda <ikeda@nskint.co.jp> |
| |
| [ Upstream commit 55cef88bbf12f3bfbe5c2379a8868a034707e755 ] |
| |
| 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 <ikeda@nskint.co.jp> |
| Link: https://lore.kernel.org/r/ed989af6-da88-4e0b-9ed8-126db6cad2e4@nskint.co.jp |
| Signed-off-by: Mark Brown <broonie@kernel.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| 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 7a00346ff9b9..13d1f0ce618e 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; |
| } |
| -- |
| 2.30.2 |
| |