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Subject[PATCH v5 1/9] x86, pci: Clean up comment about buggy MMIO config space access for AMD Fam10h CPUs.
Date
- fix typo
- improve explanation
- add reference to the related document

Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
---
arch/x86/include/asm/pci_x86.h | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/include/asm/pci_x86.h b/arch/x86/include/asm/pci_x86.h
index fa1195d..d024f4d 100644
--- a/arch/x86/include/asm/pci_x86.h
+++ b/arch/x86/include/asm/pci_x86.h
@@ -152,10 +152,13 @@ extern struct list_head pci_mmcfg_list;

/*
* AMD Fam10h CPUs are buggy, and cannot access MMIO config space
- * on their northbrige except through the * %eax register. As such, you MUST
- * NOT use normal IOMEM accesses, you need to only use the magic mmio-config
+ * on their northbridge except through the * %eax register. As such, you MUST
+ * NOT use normal IOMEM accesses, you need to only use the magic mmio_config_*
* accessor functions.
- * In fact just use pci_config_*, nothing else please.
+ *
+ * Please refer to the following doc:
+ * "BIOS and Kernel Developer's Guide (BKDG) For AMD Family 10h Processors",
+ * rev. 3.48, sec 2.11.1, "MMIO Configuration Coding Requirements".
*/
static inline unsigned char mmio_config_readb(void __iomem *pos)
{
--
1.9.1


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