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Message-id: <alpine.LFD.2.00.1101111207140.17086@xanadu.home>
Date: Tue, 11 Jan 2011 12:18:12 -0500 (EST)
From: Nicolas Pitre <nico@...xnic.net>
To: John Stultz <johnstul@...ibm.com>
Cc: lkml <linux-kernel@...r.kernel.org>
Subject: [PATCH] clocks_calc_mult_shift(): rename minsec argument according to
actual usage
The minsec argument to clocks_calc_mult_shift() is misnamed. It is used
to clamp the magnitude of the mult factor so that a multiplication with
any value in the given range won't overflow a 64 bit result. Let's
rename it to match the actual usage.
Signed-off-by: Nicolas Pitre <nicolas.pitre@...aro.org>
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index c18d7ef..8588abc 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -113,7 +113,7 @@ EXPORT_SYMBOL_GPL(timecounter_cyc2time);
* @shift: pointer to shift variable
* @from: frequency to convert from
* @to: frequency to convert to
- * @minsec: guaranteed runtime conversion range in seconds
+ * @maxsec: guaranteed runtime conversion range in seconds
*
* The function evaluates the shift/mult pair for the scaled math
* operations of clocksources and clockevents.
@@ -122,7 +122,7 @@ EXPORT_SYMBOL_GPL(timecounter_cyc2time);
* NSEC_PER_SEC == 1GHz and @from is the counter frequency. For clock
* event @to is the counter frequency and @from is NSEC_PER_SEC.
*
- * The @minsec conversion range argument controls the time frame in
+ * The @maxsec conversion range argument controls the time frame in
* seconds which must be covered by the runtime conversion with the
* calculated mult and shift factors. This guarantees that no 64bit
* overflow happens when the input value of the conversion is
@@ -131,7 +131,7 @@ EXPORT_SYMBOL_GPL(timecounter_cyc2time);
* factors.
*/
void
-clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec)
+clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 maxsec)
{
u64 tmp;
u32 sft, sftacc= 32;
@@ -140,7 +140,7 @@ clocks_calc_mult_shift(u32 *mult, u32 *shift, u32 from, u32 to, u32 minsec)
* Calculate the shift factor which is limiting the conversion
* range:
*/
- tmp = ((u64)minsec * from) >> 32;
+ tmp = ((u64)maxsec * from) >> 32;
while (tmp) {
tmp >>=1;
sftacc--;
--
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