This patch does the following changes to cpufreq-pxa2xx:
1) Simplifies the assembler code for frequency change
2) Reads back the MDREFR value to make sure data latched
3) Does as little operations in lock as possible
Signed-off-by: Marek Vasut <marek.va...@gmail.com>
---
arch/arm/mach-pxa/cpufreq-pxa2xx.c | 35 ++++++++++++++++-------------------
1 files changed, 16 insertions(+), 19 deletions(-)
diff --git a/arch/arm/mach-pxa/cpufreq-pxa2xx.c
b/arch/arm/mach-pxa/cpufreq-pxa2xx.c
index 9e4d981..1949850 100644
--- a/arch/arm/mach-pxa/cpufreq-pxa2xx.c
+++ b/arch/arm/mach-pxa/cpufreq-pxa2xx.c
@@ -297,7 +297,7 @@ static int pxa_set_target(struct cpufreq_policy *policy,
unsigned int idx;
unsigned long flags;
unsigned int new_freq_cpu, new_freq_mem;
- unsigned int unused, preset_mdrefr, postset_mdrefr, cclkcfg;
+ unsigned int preset_mdrefr, postset_mdrefr, cclkcfg;
int ret = 0;
/* Get the current policy */
@@ -355,29 +355,26 @@ static int pxa_set_target(struct cpufreq_policy *policy,
postset_mdrefr &= ~MDREFR_DB2_MASK;
}
+ /* Prepare CCLKCFG */
+ cclkcfg = pxa_freq_settings[idx].cclkcfg;
+
local_irq_save(flags);
- /* Set new the CCCR and prepare CCLKCFG */
+ /* Set new the CCCR */
CCCR = pxa_freq_settings[idx].cccr;
- cclkcfg = pxa_freq_settings[idx].cclkcfg;
asm volatile(" \n\
- ldr r4, [%1] /* load MDREFR */ \n\
- b 2f \n\
- .align 5 \n\
-1: \n\
- str %3, [%1] /* preset the MDREFR */ \n\
- mcr p14, 0, %2, c6, c0, 0 /* set CCLKCFG[FCS] */ \n\
- str %4, [%1] /* postset the MDREFR */ \n\
- \n\
- b 3f \n\
-2: b 1b \n\
-3: nop \n\
- "
- : "=&r" (unused)
- : "r" (&MDREFR), "r" (cclkcfg),
- "r" (preset_mdrefr), "r" (postset_mdrefr)
- : "r4", "r5");
+ .align 5 /* align to cache line */ \n\
+ str %2, [%0] /* preset the MDREFR */ \n\
+ ldr r4, [%0] /* make sure data latched */ \n\
+ mcr p14, 0, %1, c6, c0, 0 /* set CCLKCFG[FCS] */ \n\
+ str %3, [%0] /* postset the MDREFR */ \n\
+ ldr r4, [%0] /* make sure data latched */ \n\
+ "
+ :: "r" (&MDREFR), "r" (cclkcfg),
+ "r" (preset_mdrefr), "r" (postset_mdrefr)
+ : "r4");
+
local_irq_restore(flags);
/*
--
1.7.1
_______________________________________________
Zaurus-devel mailing list
Zaurus-devel@lists.linuxtogo.org
http://lists.linuxtogo.org/cgi-bin/mailman/listinfo/zaurus-devel
