linux-kernel - [PATCH 4/5] mfd: sprd-sc27xx-spi: Fix divide by zero when allocating register offset/mask

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Date:   Mon, 29 Jun 2020 13:32:14 +0100
From:   Lee Jones <lee.jones@...aro.org>
To:     lee.jones@...aro.org
Cc:     linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
        Orson Zhai <orsonzhai@...il.com>,
        Baolin Wang <baolin.wang7@...il.com>,
        Chunyan Zhang <zhang.lyra@...il.com>
Subject: [PATCH 4/5] mfd: sprd-sc27xx-spi: Fix divide by zero when allocating register offset/mask

Since ddata->irqs[] is already zeroed when allocated by devm_kcalloc() and
dividing 0 by anything is still 0, there is no need to re-assign
ddata->irqs[i].* values.  Instead, it should be safe to begin at 1.

This fixes the following W=1 warning:

 drivers/mfd/sprd-sc27xx-spi.c:255 sprd_pmic_probe() debug: sval_binop_unsigned: divide by zero

Cc: Orson Zhai <orsonzhai@...il.com>
Cc: Baolin Wang <baolin.wang7@...il.com>
Cc: Chunyan Zhang <zhang.lyra@...il.com>
Signed-off-by: Lee Jones <lee.jones@...aro.org>
---
 drivers/mfd/sprd-sc27xx-spi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/mfd/sprd-sc27xx-spi.c b/drivers/mfd/sprd-sc27xx-spi.c
index c305e941e435c..694a7d429ccff 100644
--- a/drivers/mfd/sprd-sc27xx-spi.c
+++ b/drivers/mfd/sprd-sc27xx-spi.c
@@ -251,7 +251,7 @@ static int sprd_pmic_probe(struct spi_device *spi)
 		return -ENOMEM;
 
 	ddata->irq_chip.irqs = ddata->irqs;
-	for (i = 0; i < pdata->num_irqs; i++) {
+	for (i = 1; i < pdata->num_irqs; i++) {
 		ddata->irqs[i].reg_offset = i / pdata->num_irqs;
 		ddata->irqs[i].mask = BIT(i % pdata->num_irqs);
 	}
-- 
2.25.1