From c2e0363571b124c4c543ad98d039d1eb319f1562 Mon Sep 17 00:00:00 2001 From: Marek Vasut Date: Tue, 14 Sep 2021 05:21:48 +0200 Subject: [PATCH] mtd: cqspi: Fix division by zero Both dummy.nbytes and dummy.buswidth may be zero. By not checking the later, it is possible to trigger division by zero and a crash. This does happen with tiny SPI NOR framework in SPL. Fix this by adding the check and returning zero dummy bytes in such a case. Fixes: 38b0852b0ea ("spi: cadence-qspi: Add support for octal DTR flashes") Signed-off-by: Marek Vasut Cc: Jagan Teki Cc: Vignesh R Cc: Pratyush Yadav [trini: Drop Pratyush's RB as his requested changes weren't made as Marek disagreed] --- drivers/spi/cadence_qspi_apb.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c index c36a652..429ee33 100644 --- a/drivers/spi/cadence_qspi_apb.c +++ b/drivers/spi/cadence_qspi_apb.c @@ -219,6 +219,9 @@ static unsigned int cadence_qspi_calc_dummy(const struct spi_mem_op *op, { unsigned int dummy_clk; + if (!op->dummy.nbytes || !op->dummy.buswidth) + return 0; + dummy_clk = op->dummy.nbytes * (8 / op->dummy.buswidth); if (dtr) dummy_clk /= 2; -- 2.7.4