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From: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
To: Ralf Baechle <ralf@linux-mips.org>, linux-mips@linux-mips.org
Cc: Linux-kernel <linux-kernel@vger.kernel.org>
Subject: [PATCH][MIPS] Malta: Fix reading the PCI clock frequency on big-endian
Date: Tue, 15 Jan 2008 00:27:46 +0300	[thread overview]
Message-ID: <478BD3D2.3060807@gmail.com> (raw)

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 <dmitri.vorobiev@gmail.com>
---
 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 b/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
 		};
-- 
1.5.3

                 reply	other threads:[~2008-01-14 21:28 UTC|newest]

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