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 <marex@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Vignesh R <vigneshr@ti.com>
Cc: Pratyush Yadav <p.yadav@ti.com>
[trini: Drop Pratyush's RB as his requested changes weren't made as
Marek disagreed]
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 @@
{
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;