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[PATCH][MIPS] Malta: Fix reading the PCI clock frequency on big-endian

To: Ralf Baechle <>,
Subject: [PATCH][MIPS] Malta: Fix reading the PCI clock frequency on big-endian
From: Dmitri Vorobiev <>
Date: Tue, 15 Jan 2008 00:27:46 +0300
Cc: Linux-kernel <>
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The JMPRS register on Malta boards keeps a 32-bit CPU-endian
value. The readw() function assumes that the value it reads is a
little-endian 16-bit number. Therefore, using readw() to obtain
the value of the JMPRS register is a mistake. This error leads
to incorrect reading of the PCI clock frequency on big-endian
during board start-up.

Change readw() to __raw_readl().

This was tested by injecting a call to printk() and verifying
that the value of the jmpr variable was consistent with current
setting of the JP4 "PCI CLK" jumper.

Signed-off-by: Dmitri Vorobiev <>
 arch/mips/mips-boards/malta/malta_setup.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/arch/mips/mips-boards/malta/malta_setup.c 
index 9a2636e..bc43a5c 100644
--- a/arch/mips/mips-boards/malta/malta_setup.c
+++ b/arch/mips/mips-boards/malta/malta_setup.c
@@ -149,7 +149,7 @@ void __init plat_mem_setup(void)
        /* Check PCI clock */
                unsigned int __iomem *jmpr_p = (unsigned int *) 
ioremap(MALTA_JMPRS_REG, sizeof(unsigned int));
-               int jmpr = (readw(jmpr_p) >> 2) & 0x07;
+               int jmpr = (__raw_readl(jmpr_p) >> 2) & 0x07;
                static const int pciclocks[] __initdata = {
                        33, 20, 25, 30, 12, 16, 37, 10

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