From mboxrd@z Thu Jan 1 00:00:00 1970 From: boris.brezillon@free-electrons.com (Boris Brezillon) Date: Mon, 31 Jul 2017 18:28:40 +0200 Subject: [PATCH] mtd: nand: sunxi: fix potential divide-by-zero error In-Reply-To: <1501248177-575-1-git-send-email-pure.logic@nexus-software.ie> References: <1501248177-575-1-git-send-email-pure.logic@nexus-software.ie> Message-ID: <20170731182840.4cdca90d@bbrezillon> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Fri, 28 Jul 2017 14:22:57 +0100 Bryan O'Donoghue wrote: > clk_round_rate() can return <= 0. Currently the value returned by > clk_round_rate() is used directly for a division. This patch introduces a > guard to ensure a divide-by-zero or a divide by a negative number for that > matter can't happen by bugging out returning -EINVAL if clk_round_rate() > returns <= 0. Applied to nand/fixes. Thanks, Boris > > Fixes: 2d43457f79e4 ("mtd: nand: sunxi: fix EDO mode selection") > > Signed-off-by: Bryan O'Donoghue > --- > drivers/mtd/nand/sunxi_nand.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/drivers/mtd/nand/sunxi_nand.c b/drivers/mtd/nand/sunxi_nand.c > index d0b6f8f..6abd142 100644 > --- a/drivers/mtd/nand/sunxi_nand.c > +++ b/drivers/mtd/nand/sunxi_nand.c > @@ -1728,6 +1728,10 @@ static int sunxi_nfc_setup_data_interface(struct mtd_info *mtd, int csline, > */ > chip->clk_rate = NSEC_PER_SEC / min_clk_period; > real_clk_rate = clk_round_rate(nfc->mod_clk, chip->clk_rate); > + if (real_clk_rate <= 0) { > + dev_err(nfc->dev, "Unable to round clk %lu\n", chip->clk_rate); > + return -EINVAL; > + } > > /* > * ONFI specification 3.1, paragraph 4.15.2 dictates that EDO data