From 51bc4a01332cce55d1627edb8b65a814292bfc31 Mon Sep 17 00:00:00 2001
From: Olof Johansson <olof@lixom.net>
Date: Sat, 8 Sep 2007 05:13:19 +1000
Subject: [PATCH] --- yaml --- r: 67305 b: refs/heads/master c:
 0d72ba930cbc9140a584af7e4e65041b6c7a7d18 h: refs/heads/master i:   67303:
 9267dbffba1af973a801a9e454f8d5b6ea55cf40 v: v3

---
 [refs]                                      |  2 +-
 trunk/arch/powerpc/platforms/Kconfig        | 10 ++++++++++
 trunk/arch/powerpc/platforms/pasemi/Kconfig |  1 +
 trunk/arch/powerpc/sysdev/mpic.c            | 14 ++++++++++++--
 trunk/include/asm-powerpc/mpic.h            |  4 ++++
 5 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index 65775e3d20aa..cb12c8dd8344 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 2099172d61abda1b793b499bb8edcaac4de2cdae
+refs/heads/master: 0d72ba930cbc9140a584af7e4e65041b6c7a7d18
diff --git a/trunk/arch/powerpc/platforms/Kconfig b/trunk/arch/powerpc/platforms/Kconfig
index 065f3b19d6c7..78a7edac577f 100644
--- a/trunk/arch/powerpc/platforms/Kconfig
+++ b/trunk/arch/powerpc/platforms/Kconfig
@@ -137,6 +137,16 @@ config MPIC_U3_HT_IRQS
 	depends on PPC_MAPLE
 	default y
 
+config MPIC_BROKEN_REGREAD
+	bool
+	depends on MPIC
+	help
+	  This option enables a MPIC driver workaround for some chips
+	  that have a bug that causes some interrupt source information
+	  to not read back properly. It is safe to use on other chips as
+	  well, but enabling it uses about 8KB of memory to keep copies
+	  of the register contents in software.
+
 config IBMVIO
 	depends on PPC_PSERIES || PPC_ISERIES
 	bool
diff --git a/trunk/arch/powerpc/platforms/pasemi/Kconfig b/trunk/arch/powerpc/platforms/pasemi/Kconfig
index 95cd90fd81c7..117d90aa5008 100644
--- a/trunk/arch/powerpc/platforms/pasemi/Kconfig
+++ b/trunk/arch/powerpc/platforms/pasemi/Kconfig
@@ -5,6 +5,7 @@ config PPC_PASEMI
 	select MPIC
 	select PPC_UDBG_16550
 	select PPC_NATIVE
+	select MPIC_BROKEN_REGREAD
 	help
 	  This option enables support for PA Semi's PWRficient line
 	  of SoC processors, including PA6T-1682M
diff --git a/trunk/arch/powerpc/sysdev/mpic.c b/trunk/arch/powerpc/sysdev/mpic.c
index 25a81f73cecf..8de29f28b4c7 100644
--- a/trunk/arch/powerpc/sysdev/mpic.c
+++ b/trunk/arch/powerpc/sysdev/mpic.c
@@ -228,8 +228,13 @@ static inline u32 _mpic_irq_read(struct mpic *mpic, unsigned int src_no, unsigne
 	unsigned int	isu = src_no >> mpic->isu_shift;
 	unsigned int	idx = src_no & mpic->isu_mask;
 
-	return _mpic_read(mpic->reg_type, &mpic->isus[isu],
-			  reg + (idx * MPIC_INFO(IRQ_STRIDE)));
+#ifdef CONFIG_MPIC_BROKEN_REGREAD
+	if (reg == 0)
+		return mpic->isu_reg0_shadow[idx];
+	else
+#endif
+		return _mpic_read(mpic->reg_type, &mpic->isus[isu],
+				  reg + (idx * MPIC_INFO(IRQ_STRIDE)));
 }
 
 static inline void _mpic_irq_write(struct mpic *mpic, unsigned int src_no,
@@ -240,6 +245,11 @@ static inline void _mpic_irq_write(struct mpic *mpic, unsigned int src_no,
 
 	_mpic_write(mpic->reg_type, &mpic->isus[isu],
 		    reg + (idx * MPIC_INFO(IRQ_STRIDE)), value);
+
+#ifdef CONFIG_MPIC_BROKEN_REGREAD
+	if (reg == 0)
+		mpic->isu_reg0_shadow[idx] = value;
+#endif
 }
 
 #define mpic_read(b,r)		_mpic_read(mpic->reg_type,&(b),(r))
diff --git a/trunk/include/asm-powerpc/mpic.h b/trunk/include/asm-powerpc/mpic.h
index 0eb3ab9ec2bb..edb4a7c84506 100644
--- a/trunk/include/asm-powerpc/mpic.h
+++ b/trunk/include/asm-powerpc/mpic.h
@@ -306,6 +306,10 @@ struct mpic
 	unsigned long		*hwirq_bitmap;
 #endif
 
+#ifdef CONFIG_MPIC_BROKEN_REGREAD
+	u32			isu_reg0_shadow[MPIC_MAX_IRQ_SOURCES];
+#endif
+
 	/* link */
 	struct mpic		*next;