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clocksource: Fix clocksource_mmio_readX_down

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For some clocksource devices, for example, the registers are 32-bit, while
the lower 16-bit is used for timer counting(And reading the upper 16-bit
will return 0).

For example, when the counter value is 0x00001111, and then the
~readl_relaxed(to_mmio_clksrc(c)->reg) will return the value of 0xFFFFEEEE,
but it should be 0x0000EEEE.

So just using the c->mask to mask the unused bits.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Xiubo Li 2014-04-23 10:12:00 +08:00 committed by Daniel Lezcano
parent 4a3ae07413
commit 95c19a06ec
1 changed files with 2 additions and 2 deletions
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4
drivers/clocksource/mmio.c
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@ -27,7 +27,7 @@ cycle_t clocksource_mmio_readl_up(struct clocksource *c)
cycle_t clocksource_mmio_readl_down(struct clocksource *c) cycle_t clocksource_mmio_readl_down(struct clocksource *c)
{ {
return ~(cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg); return ~(cycle_t)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
} }
cycle_t clocksource_mmio_readw_up(struct clocksource *c) cycle_t clocksource_mmio_readw_up(struct clocksource *c)
@ -37,7 +37,7 @@ cycle_t clocksource_mmio_readw_up(struct clocksource *c)
cycle_t clocksource_mmio_readw_down(struct clocksource *c) cycle_t clocksource_mmio_readw_down(struct clocksource *c)
{ {
return ~(cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg); return ~(cycle_t)readw_relaxed(to_mmio_clksrc(c)->reg) & c->mask;
} }
/** /**