LKML Archive on lore.kernel.org
help / color / mirror / Atom feed
From: Geert Uytterhoeven <geert+renesas@glider.be>
To: Mike Turquette <mturquette@linaro.org>,
	Stephen Boyd <sboyd@codeaurora.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Ulrich Hecht <ulrich.hecht+renesas@gmail.com>,
	Wolfram Sang <wsa@sang-engineering.com>,
	linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org,
	Geert Uytterhoeven <geert+renesas@glider.be>
Subject: [PATCH] clk: shmobile: div6: Avoid division by zero in .round_rate()
Date: Wed,  4 Feb 2015 13:27:21 +0100	[thread overview]
Message-ID: <1423052841-15194-1-git-send-email-geert+renesas@glider.be> (raw)

Anyone may call clk_round_rate() with a zero rate value, so we have to
protect against that.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
This was triggered by the bad version of "clk: Add rate constraints to
clocks", but can happen regardless, cfr.
https://lkml.org/lkml/2015/1/29/560

 drivers/clk/shmobile/clk-div6.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/clk/shmobile/clk-div6.c b/drivers/clk/shmobile/clk-div6.c
index efbaf6c81b7530b8..036a692c72195db9 100644
--- a/drivers/clk/shmobile/clk-div6.c
+++ b/drivers/clk/shmobile/clk-div6.c
@@ -90,6 +90,9 @@ static unsigned int cpg_div6_clock_calc_div(unsigned long rate,
 {
 	unsigned int div;
 
+	if (!rate)
+		rate = 1;
+
 	div = DIV_ROUND_CLOSEST(parent_rate, rate);
 	return clamp_t(unsigned int, div, 1, 64);
 }
-- 
1.9.1


             reply	other threads:[~2015-02-04 12:27 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-04 12:27 Geert Uytterhoeven [this message]
2015-02-04 13:31 ` Sergei Shtylyov
2015-02-04 13:50   ` Laurent Pinchart
2015-02-04 17:32 ` Wolfram Sang
2015-02-04 17:45   ` Sergei Shtylyov
2015-02-04 22:01     ` Mike Turquette
2015-02-04 22:04       ` Sergei Shtylyov
2015-02-04 22:14         ` Sergei Shtylyov
2015-02-05 17:19           ` Laurent Pinchart
2015-02-05 17:46             ` Mike Turquette
2015-02-06 11:12             ` Sergei Shtylyov
2015-02-04 22:05   ` Mike Turquette

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1423052841-15194-1-git-send-email-geert+renesas@glider.be \
    --to=geert+renesas@glider.be \
    --cc=laurent.pinchart@ideasonboard.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-sh@vger.kernel.org \
    --cc=mturquette@linaro.org \
    --cc=sboyd@codeaurora.org \
    --cc=ulrich.hecht+renesas@gmail.com \
    --cc=wsa@sang-engineering.com \
    --subject='Re: [PATCH] clk: shmobile: div6: Avoid division by zero in .round_rate()' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).