evie/android_kernel_oneplus_msm8998
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mmc: core: Log MMC clock frequency transitions

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Use kernel's ftrace support to capture MMC clock frequency
transitions which can be useful for debugging issues related
to power consumption.

Usage:
mount -t debugfs none /sys/kernel/debug
echo 1 > /sys/kernel/debug/tracing/events/mmc/mmc_clk/enable
cat /sys/kernel/debug/tracing/trace_pipe

Change-Id: I25c4ee39dcbe30e7665902a9f723a5a421b55ca3
Signed-off-by: Sujit Reddy Thumma <sthumma@codeaurora.org>
This commit is contained in:
Sujit Reddy Thumma 2013-02-14 08:13:52 +05:30 • committed by Subhash Jadavani
parent 553d6cb4e2
commit b4b98fb480
3 changed files with 34 additions and 1 deletions
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13
drivers/mmc/core/core.c
View file

@ -1122,6 +1122,19 @@ void mmc_set_ios(struct mmc_host *host)
if (ios->clock > 0) if (ios->clock > 0)
mmc_set_ungated(host); mmc_set_ungated(host);
host->ops->set_ios(host, ios); host->ops->set_ios(host, ios);
if (ios->old_rate != ios->clock) {
if (likely(ios->clk_ts)) {
char trace_info[80];
snprintf(trace_info, 80,
"%s: freq_KHz %d --> %d | t = %d",
mmc_hostname(host), ios->old_rate / 1000,
ios->clock / 1000, jiffies_to_msecs(
(long)jiffies - (long)ios->clk_ts));
trace_mmc_clk(trace_info);
}
ios->old_rate = ios->clock;
ios->clk_ts = jiffies;
}
} }
EXPORT_SYMBOL(mmc_set_ios); EXPORT_SYMBOL(mmc_set_ios);

2
include/linux/mmc/host.h
View file

@ -23,6 +23,8 @@
struct mmc_ios { struct mmc_ios {
unsigned int clock; /* clock rate */ unsigned int clock; /* clock rate */
unsigned int old_rate; /* saved clock rate */
unsigned long clk_ts; /* time stamp of last updated clock */
unsigned short vdd; unsigned short vdd;
/* vdd stores the bit number of the selected voltage range from below. */ /* vdd stores the bit number of the selected voltage range from below. */

20
include/trace/events/mmc.h
View file

@ -158,7 +158,25 @@ DEFINE_EVENT(mmc_adma_class, mmc_adma_table_post,
TP_PROTO(unsigned int cmd, unsigned int len), TP_PROTO(unsigned int cmd, unsigned int len),
TP_ARGS(cmd, len)); TP_ARGS(cmd, len));
#endif /* _TRACE_MMC_H */ TRACE_EVENT(mmc_clk,
TP_PROTO(char *print_info),
TP_ARGS(print_info),
TP_STRUCT__entry(
__string(print_info, print_info)
),
TP_fast_assign(
__assign_str(print_info, print_info);
),
TP_printk("%s",
__get_str(print_info)
)
);
#endif /* if !defined(_TRACE_MMC_H) || defined(TRACE_HEADER_MULTI_READ) */
/* This part must be outside protection */ /* This part must be outside protection */
#include <trace/define_trace.h> #include <trace/define_trace.h>