[PATCH] Fix mmap() of /dev/hpet

From: Keir Fraser
Date: Thu Sep 22 2005 - 07:05:14 EST


The address passed to io_remap_pfn_range() in hpet_mmap() does not
need to be converted using __pa(): it is already a physical
address. This bug was found and the patch suggested by Clay Harris.

I introduced this particular bug when making io_remap_pfn_range
changes a few months ago. In fact mmap()ing /dev/hpet has *never*
previously worked: before my changes __pa() was being executed on an
ioremap()ed virtual address, which is also invalid.

Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>

diff -urpP linux-2.6.14-rc2.old/drivers/char/hpet.c linux-2.6.14-rc2.new/drivers/char/hpet.c
--- linux-2.6.14-rc2.old/drivers/char/hpet.c 2005-09-22 12:47:00.773424663 +0100
+++ linux-2.6.14-rc2.new/drivers/char/hpet.c 2005-09-22 12:47:18.216928551 +0100
@@ -273,7 +273,6 @@ static int hpet_mmap(struct file *file,

vma->vm_flags |= VM_IO;
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- addr = __pa(addr);

if (io_remap_pfn_range(vma, vma->vm_start, addr >> PAGE_SHIFT,
PAGE_SIZE, vma->vm_page_prot)) {