linux-kernel - [PATCH v2 3/3] ARM: da850: fix da850_set

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Date:   Fri,  2 Dec 2016 16:38:54 +0100
From:   Bartosz Golaszewski <bgolaszewski@...libre.com>
To:     Kevin Hilman <khilman@...libre.com>,
        Michael Turquette <mturquette@...libre.com>,
        Sekhar Nori <nsekhar@...com>,
        Peter Ujfalusi <peter.ujfalusi@...com>,
        Russell King <linux@...linux.org.uk>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Boris Brezillon <boris.brezillon@...e-electrons.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Richard Weinberger <richard@....at>,
        David Woodhouse <dwmw2@...radead.org>,
        Brian Norris <computersforpeace@...il.com>,
        Marek Vasut <marek.vasut@...il.com>,
        Cyrille Pitchen <cyrille.pitchen@...el.com>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        arm-soc <linux-arm-kernel@...ts.infradead.org>,
        linux-pm@...r.kernel.org,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: [PATCH v2 3/3] ARM: da850: fix da850_set_pll0rate()

This function is broken - its second argument is an index to the freq
table, not the requested clock rate in Hz. It leads to an oops when
called from clk_set_rate() since this argument isn't bounds checked
either.

Fix it by iterating over the array of supported frequencies and
selecting a one that matches or returning -EINVAL for unsupported
rates.

Also: update the davinci cpufreq driver. It's the only user of this
clock and currently it passes the cpufreq table index to
clk_set_rate(), which is confusing. Make it pass the requested clock
rate in Hz.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@...libre.com>
---
 arch/arm/mach-davinci/da850.c     | 22 ++++++++++++++++++----
 drivers/cpufreq/davinci-cpufreq.c |  2 +-
 2 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c
index a55101c..92e3303 100644
--- a/arch/arm/mach-davinci/da850.c
+++ b/arch/arm/mach-davinci/da850.c
@@ -1179,14 +1179,28 @@ static int da850_set_armrate(struct clk *clk, unsigned long index)
 	return clk_set_rate(pllclk, index);
 }
 
-static int da850_set_pll0rate(struct clk *clk, unsigned long index)
+static int da850_set_pll0rate(struct clk *clk, unsigned long rate)
 {
-	unsigned int prediv, mult, postdiv;
-	struct da850_opp *opp;
 	struct pll_data *pll = clk->pll_data;
+	struct cpufreq_frequency_table *freq;
+	unsigned int prediv, mult, postdiv;
+	struct da850_opp *opp = NULL;
 	int ret;
 
-	opp = (struct da850_opp *) cpufreq_info.freq_table[index].driver_data;
+	for (freq = da850_freq_table;
+	     freq->frequency != CPUFREQ_TABLE_END; freq++) {
+		/* requested_rate is in Hz, freq->frequency is in KHz */
+		unsigned long freq_rate = freq->frequency * 1000;
+
+		if (freq_rate == rate) {
+			opp = (struct da850_opp *)freq->driver_data;
+			break;
+		}
+	}
+
+	if (opp == NULL)
+		return -EINVAL;
+
 	prediv = opp->prediv;
 	mult = opp->mult;
 	postdiv = opp->postdiv;
diff --git a/drivers/cpufreq/davinci-cpufreq.c b/drivers/cpufreq/davinci-cpufreq.c
index b95a872..d54a27c 100644
--- a/drivers/cpufreq/davinci-cpufreq.c
+++ b/drivers/cpufreq/davinci-cpufreq.c
@@ -55,7 +55,7 @@ static int davinci_target(struct cpufreq_policy *policy, unsigned int idx)
 			return ret;
 	}
 
-	ret = clk_set_rate(armclk, idx);
+	ret = clk_set_rate(armclk, new_freq * 1000);
 	if (ret)
 		return ret;
 
-- 
2.9.3