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authorPaul Walmsley <paul@pwsan.com>2009-12-08 16:33:16 -0700
committerpaul <paul@twilight.(none)>2009-12-11 17:00:43 -0700
commit6f8b7ff5b01e16a65c3b17865ce047faeca40907 (patch)
treeae5ecb4b377588b157c23176cf95a5c9631206ba
parent3863c74b512c1afd3ce6b2f81d8dea9f1d860968 (diff)
OMAP clock/hwmod: fix off-by-one errors
Fix loop bailout off-by-one bugs reported by Juha Leppänen <juha_motorsportcom@luukku.com>. This second version incorporates comments from Russell King <linux@arm.linux.org.uk>. A new macro, 'omap_test_timeout', has been created, with cleaner code, and existing code has been converted to use it. Signed-off-by: Paul Walmsley <paul@pwsan.com> Cc: Juha Leppänen <juha_motorsportcom@luukku.com> Cc: Russell King <linux@arm.linux.org.uk>
-rw-r--r--arch/arm/mach-omap2/cm.c7
-rw-r--r--arch/arm/mach-omap2/omap_hwmod.c13
-rw-r--r--arch/arm/mach-omap2/prcm.c5
-rw-r--r--arch/arm/plat-omap/include/plat/common.h20
4 files changed, 31 insertions, 14 deletions
diff --git a/arch/arm/mach-omap2/cm.c b/arch/arm/mach-omap2/cm.c
index 8eb2dab8c7d..58e4a1c557d 100644
--- a/arch/arm/mach-omap2/cm.c
+++ b/arch/arm/mach-omap2/cm.c
@@ -21,6 +21,8 @@
#include <asm/atomic.h>
+#include <plat/common.h>
+
#include "cm.h"
#include "cm-regbits-24xx.h"
#include "cm-regbits-34xx.h"
@@ -61,9 +63,8 @@ int omap2_cm_wait_module_ready(s16 prcm_mod, u8 idlest_id, u8 idlest_shift)
mask = 1 << idlest_shift;
/* XXX should be OMAP2 CM */
- while (((cm_read_mod_reg(prcm_mod, cm_idlest_reg) & mask) != ena) &&
- (i++ < MAX_MODULE_READY_TIME))
- udelay(1);
+ omap_test_timeout(((cm_read_mod_reg(prcm_mod, cm_idlest_reg) & mask) == ena),
+ MAX_MODULE_READY_TIME, i);
return (i < MAX_MODULE_READY_TIME) ? 0 : -EBUSY;
}
diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
index 633b216a8b2..7aaf5f1eea7 100644
--- a/arch/arm/mach-omap2/omap_hwmod.c
+++ b/arch/arm/mach-omap2/omap_hwmod.c
@@ -45,6 +45,7 @@
#include <linux/mutex.h>
#include <linux/bootmem.h>
+#include <plat/common.h>
#include <plat/cpu.h>
#include <plat/clockdomain.h>
#include <plat/powerdomain.h>
@@ -736,7 +737,7 @@ static int _wait_target_ready(struct omap_hwmod *oh)
static int _reset(struct omap_hwmod *oh)
{
u32 r, v;
- int c;
+ int c = 0;
if (!oh->sysconfig ||
!(oh->sysconfig->sysc_flags & SYSC_HAS_SOFTRESET) ||
@@ -758,13 +759,9 @@ static int _reset(struct omap_hwmod *oh)
return r;
_write_sysconfig(v, oh);
- c = 0;
- while (c < MAX_MODULE_RESET_WAIT &&
- !(omap_hwmod_readl(oh, oh->sysconfig->syss_offs) &
- SYSS_RESETDONE_MASK)) {
- udelay(1);
- c++;
- }
+ omap_test_timeout((omap_hwmod_readl(oh, oh->sysconfig->syss_offs) &
+ SYSS_RESETDONE_MASK),
+ MAX_MODULE_RESET_WAIT, c);
if (c == MAX_MODULE_RESET_WAIT)
WARN(1, "omap_hwmod: %s: failed to reset in %d usec\n",
diff --git a/arch/arm/mach-omap2/prcm.c b/arch/arm/mach-omap2/prcm.c
index 9208b6e873a..79637c2eaf6 100644
--- a/arch/arm/mach-omap2/prcm.c
+++ b/arch/arm/mach-omap2/prcm.c
@@ -241,9 +241,8 @@ int omap2_cm_wait_idlest(void __iomem *reg, u32 mask, const char *name)
BUG();
/* Wait for lock */
- while (((__raw_readl(reg) & mask) != ena) &&
- (i++ < MAX_MODULE_ENABLE_WAIT))
- udelay(1);
+ omap_test_timeout(((__raw_readl(reg) & mask) == ena),
+ MAX_MODULE_ENABLE_WAIT, i);
if (i < MAX_MODULE_ENABLE_WAIT)
pr_debug("cm: Module associated with clock %s ready after %d "
diff --git a/arch/arm/plat-omap/include/plat/common.h b/arch/arm/plat-omap/include/plat/common.h
index 064f1730f43..e9779676448 100644
--- a/arch/arm/plat-omap/include/plat/common.h
+++ b/arch/arm/plat-omap/include/plat/common.h
@@ -71,4 +71,24 @@ void omap2_set_globals_sdrc(struct omap_globals *);
void omap2_set_globals_control(struct omap_globals *);
void omap2_set_globals_prcm(struct omap_globals *);
+/**
+ * omap_test_timeout - busy-loop, testing a condition
+ * @cond: condition to test until it evaluates to true
+ * @timeout: maximum number of microseconds in the timeout
+ * @index: loop index (integer)
+ *
+ * Loop waiting for @cond to become true or until at least @timeout
+ * microseconds have passed. To use, define some integer @index in the
+ * calling code. After running, if @index == @timeout, then the loop has
+ * timed out.
+ */
+#define omap_test_timeout(cond, timeout, index) \
+({ \
+ for (index = 0; index < timeout; index++) { \
+ if (cond) \
+ break; \
+ udelay(1); \
+ } \
+})
+
#endif /* __ARCH_ARM_MACH_OMAP_COMMON_H */