From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
To: Sekhar Nori <nsekhar@ti.com>
Cc: Kevin Hilman <khilman@baylibre.com>,
Michael Turquette <mturquette@baylibre.com>,
Peter Ujfalusi <peter.ujfalusi@ti.com>,
Russell King <linux@armlinux.org.uk>,
Viresh Kumar <viresh.kumar@linaro.org>,
Boris Brezillon <boris.brezillon@free-electrons.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Richard Weinberger <richard@nod.at>,
David Woodhouse <dwmw2@infradead.org>,
Brian Norris <computersforpeace@gmail.com>,
Marek Vasut <marek.vasut@gmail.com>,
Cyrille Pitchen <cyrille.pitchen@atmel.com>,
LKML <linux-kernel@vger.kernel.org>,
arm-soc <linux-arm-kernel@lists.infradead.org>,
linux-pm <linux-pm@vger.kernel.org>
Subject: Re: [PATCH v2 3/3] ARM: da850: fix da850_set_pll0rate()
Date: Mon, 5 Dec 2016 10:07:46 +0100 [thread overview]
Message-ID: <CAMpxmJWCmhKvM=Dgn+bnFfnuO9NGghPURVXuzxW2Vym0Y-akOg@mail.gmail.com> (raw)
In-Reply-To: <130825f1-5c8f-f6bc-1f27-929ff591a9c3@ti.com>
2016-12-05 9:45 GMT+01:00 Sekhar Nori <nsekhar@ti.com>:
> On Friday 02 December 2016 09:08 PM, Bartosz Golaszewski wrote:
>> 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@baylibre.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;
>
> A small optimization here. Instead of multiplying potentially every
> frequency in the table by 1000, you could divide the incoming rate down
> to KHz. This will also avoid the need for 'freq_rate'. Should have
> noticed this earlier. Sorry about that.
>
> Thanks,
> Sekhar
I thought about it, but figured the multiplication would be safer. I
will change it if you prefer this version.
Best regards,
Bartosz Golaszewski
prev parent reply other threads:[~2016-12-05 9:18 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-02 15:38 [PATCH v2 0/3] ARM: da850: fix pll0 rate setting Bartosz Golaszewski
2016-12-02 15:38 ` [PATCH v2 1/3] ARM: da850: fix infinite loop in clk_set_rate() Bartosz Golaszewski
2016-12-05 8:38 ` Sekhar Nori
2016-12-05 9:06 ` Bartosz Golaszewski
2016-12-02 15:38 ` [PATCH v2 2/3] ARM: da850: coding style fix Bartosz Golaszewski
2016-12-02 15:38 ` [PATCH v2 3/3] ARM: da850: fix da850_set_pll0rate() Bartosz Golaszewski
2016-12-05 3:34 ` Viresh Kumar
2016-12-05 8:45 ` Sekhar Nori
2016-12-05 9:07 ` Bartosz Golaszewski [this message]
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