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authorJohn Rigby <john.rigby@linaro.org>2010-12-27 14:33:10 +0000
committerAlbert ARIBAUD <albert.u.boot@aribaud.net>2011-07-04 10:55:26 +0200
commitaadcfc179a5f9ef61c8201da9dff34f8394c1054 (patch)
tree579d3a0accadd0ebdab5155bf13b353d447fac36 /arch/arm/cpu/armv7/omap-common
parentf84d64dbf69e84b34140219e630641079fdef37f (diff)
downloadblackbird-obmc-uboot-aadcfc179a5f9ef61c8201da9dff34f8394c1054.tar.gz
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OMAP[34]: fix broken timer
As implemented now the timer used to implement __udelay counts to 0xffffffff and then gets stuck there because the the programmed reload value is 0xffffffff. This value is not only wrong but illegal according to the reference manual. One can reproduce the bug by leaving a board at the u-boot prompt for sometime then issuing a sleep command. The sleep will hang forever. The timer is a count up timer that reloads as it rolls over from 0xffffffff so the correct load value is 0. Change TIMER_LOAD_VAL from 0xffffffff to 0 and introduce a new constant called TIMER_OVERFLOW_VAL set to 0xffffffff. Signed-off-by: John Rigby <john.rigby@linaro.org> Tested-by: Igor Grinberg <grinberg@compulab.co.il>
Diffstat (limited to 'arch/arm/cpu/armv7/omap-common')
-rw-r--r--arch/arm/cpu/armv7/omap-common/timer.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/arm/cpu/armv7/omap-common/timer.c b/arch/arm/cpu/armv7/omap-common/timer.c
index 9beebb1e74..59bbca84a6 100644
--- a/arch/arm/cpu/armv7/omap-common/timer.c
+++ b/arch/arm/cpu/armv7/omap-common/timer.c
@@ -43,8 +43,9 @@ static struct gptimer *timer_base = (struct gptimer *)CONFIG_SYS_TIMERBASE;
* Nothing really to do with interrupts, just starts up a counter.
*/
-#define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
-#define TIMER_LOAD_VAL 0xffffffff
+#define TIMER_CLOCK (V_SCLK / (2 << CONFIG_SYS_PTV))
+#define TIMER_OVERFLOW_VAL 0xffffffff
+#define TIMER_LOAD_VAL 0
int timer_init(void)
{
@@ -86,7 +87,7 @@ void __udelay(unsigned long usec)
while (tmo > 0) {
now = readl(&timer_base->tcrr);
if (last > now) /* count up timer overflow */
- tmo -= TIMER_LOAD_VAL - last + now;
+ tmo -= TIMER_OVERFLOW_VAL - last + now + 1;
else
tmo -= now - last;
last = now;
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