[PATCH 3/3] ARM: da850: fix da850_set_pll0rate()
From: Sekhar Nori <hidden>
Date: 2016-12-02 11:21:32
Also in:
lkml
On Thursday 01 December 2016 10:45 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. Signed-off-by: Bartosz Golaszewski <redacted>
When this function was written, it was written for speed. The only user of setting pll0 rate is drivers/cpufreq/davinci-cpufreq.c (not sure how you were trying to set pll0 rate). And that driver directly passes the table index to the set_rate() function. The idea was to optimize for speed in cpufreq driver and quickly index into the pll data instead of searching through it. But I agree, it is confusing and we are better off with maintainable code. So, no problem with the patch, but this needs to be done along with updates to cpufreq driver.
quoted hunk ↗ jump to hunk
--- arch/arm/mach-davinci/da850.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-)diff --git a/arch/arm/mach-davinci/da850.c b/arch/arm/mach-davinci/da850.c index 855b720..1c0f296 100644 --- a/arch/arm/mach-davinci/da850.c +++ b/arch/arm/mach-davinci/da850.c@@ -1173,14 +1173,28 @@ 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 requested_rate)
Calling it just 'rate' is fine, IMO. The name of the function is enough to suggest that its the rate to be set to. Thanks, Sekhar