ARM: cti: fix manipulation of debug lock registers

The LOCKSTATUS register for memory-mapped coresight devices indicates whether or not the device in question implements hardware locking. If not, locking is not present (i.e. LSR.SLI == 0) and LAR is write-ignore, so software doesn't actually need to check the status register at all.

This patch removes the broken LSR checks.

Cc Ming Lei <[email protected]>

Reported-by Mike Williams <[email protected]>

Signed-off-by Will Deacon <[email protected]>

---
 arch/arm/include/asm/cti.h |   20 ++------------------
 1 files changed, 2 insertions(+), 18 deletions(-)

arch/arm/include/asm/cti.h +1 -11

index a0ada3e..f2e5cad 100644
@@ -146,15 +146,7 @@ static inline void cti_irq_ack(struct cti *cti)
  */
 static inline void cti_unlock(struct cti *cti)
 {
-	void __iomem *base = cti->base;
-	unsigned long val;
-
-	val = __raw_readl(base + LOCKSTATUS);
-
-	if (val & 1) {
-		val = LOCKCODE;
-		__raw_writel(val, base + LOCKACCESS);
-	}
+	__raw_writel(LOCKCODE, cti->base + LOCKACCESS);
 }
 
 /**

@@ -166,14 +158,6 @@ static inline void cti_unlock(struct cti *cti)
  */
 static inline void cti_lock(struct cti *cti)
 {
-	void __iomem *base = cti->base;
-	unsigned long val;

Quoted 27 lines · Will Deacon

arch/arm/include/asm/cti.h +1 -11

index a0ada3e..f2e5cad 100644
@@ -146,15 +146,7 @@ static inline void cti_irq_ack(struct cti *cti)
  */
 static inline void cti_unlock(struct cti *cti)
 {
-	void __iomem *base = cti->base;
-	unsigned long val;
-
-	val = __raw_readl(base + LOCKSTATUS);
-
-	if (val & 1) {
-		val = LOCKCODE;
-		__raw_writel(val, base + LOCKACCESS);
-	}
+	__raw_writel(LOCKCODE, cti->base + LOCKACCESS);
 }
 
 /**

@@ -166,14 +158,6 @@ static inline void cti_unlock(struct cti *cti)
  */
 static inline void cti_lock(struct cti *cti)
 {
-	void __iomem *base = cti->base;
-	unsigned long val;

arch/arm/include/asm/cti.h static inline void cti_unlock(struct cti *cti) · line 163

Quoted 10 lines

arch/arm/include/asm/cti.h +1 -7

-
-	val = __raw_readl(base + LOCKSTATUS);
-
-	if (!(val & 1)) {
-		val = ~LOCKCODE;
-		__raw_writel(val, base + LOCKACCESS);
-	}
+	__raw_writel(~LOCKCODE, cti->base + LOCKACCESS);
 }
 #endif

I gave this a whirl on omap4430 and PMU is working fine with this, so ...

Tested-by Jon Hunter <[email protected]>