[PATCH] Reserve only needed regions for PC timers on i386 and x86_64

ChangeSet 1.1549, 2005/02/23 04:23:33-03:00, [email protected]

	[PATCH] Reserve only needed regions for PC timers on i386 and x86_64
	
	Date: Mon, 21 Feb 2005 14:06:18 +0100
	From: Charles-Edouard Ruault <[email protected]>
	To: [email protected], [email protected]
	Cc: Alan Cox <[email protected]>, Linux Kernel Mailing List <[email protected]>
	Subject: [PATCH] Reserve only needed regions for PC timers on i386 and x86_64
	
	>>- Why is the generic timer using this address ? isn't it reserving a too
	>>wide portion of IO ports ? Should it be modified for this board ?
	>
	>It just reserved the entire chip space since way back when.
	>
	>>-  If there's a good reason for the timer to request this address, is
	>>there a clean way to share it with the timer ?
	>
	>Submit a small patch to Linus/Andrew to make the generic code only
	>reserve the ports it should. It's just a historical oversight
	
	Linus, Andrew,
	As suggested by Alan, here's a small patch against kernel 2.4.29 to
	split the IO addresses reserved for the  PC timer into two regions
	instead of a large one.
	It mimics what has been done in kernel 2.6.
	Instead of reserving 0x40 through 0x5f it reserves only what the two
	timers need, i.e 0x40-0x43 and 0x50-0x53.
	It patches both i386 and x86_64 architecture.
	
	Please CC me in replies since i did not subscribe to the list.



 i386/kernel/setup.c   |    3 ++-
 x86_64/kernel/setup.c |    3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)


diff -Nru a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c
--- a/arch/i386/kernel/setup.c	2005-02-24 15:01:59 -08:00
+++ b/arch/i386/kernel/setup.c	2005-02-24 15:01:59 -08:00
@@ -354,7 +354,8 @@
 struct resource standard_io_resources[] = {
 	{ "dma1", 0x00, 0x1f, IORESOURCE_BUSY },
 	{ "pic1", 0x20, 0x3f, IORESOURCE_BUSY },
-	{ "timer", 0x40, 0x5f, IORESOURCE_BUSY },
+	{ "timer0", 0x40, 0x43, IORESOURCE_BUSY },
+	{ "timer1", 0x50, 0x53, IORESOURCE_BUSY },
 	{ "keyboard", 0x60, 0x6f, IORESOURCE_BUSY },
 	{ "dma page reg", 0x80, 0x8f, IORESOURCE_BUSY },
 	{ "pic2", 0xa0, 0xbf, IORESOURCE_BUSY },
diff -Nru a/arch/x86_64/kernel/setup.c b/arch/x86_64/kernel/setup.c
--- a/arch/x86_64/kernel/setup.c	2005-02-24 15:01:59 -08:00
+++ b/arch/x86_64/kernel/setup.c	2005-02-24 15:01:59 -08:00
@@ -93,7 +93,8 @@
 struct resource standard_io_resources[] = {
 	{ "dma1", 0x00, 0x1f, IORESOURCE_BUSY },
 	{ "pic1", 0x20, 0x3f, IORESOURCE_BUSY },
-	{ "timer", 0x40, 0x5f, IORESOURCE_BUSY },
+	{ "timer0", 0x40, 0x43, IORESOURCE_BUSY },
+	{ "timer1", 0x50, 0x53, IORESOURCE_BUSY },
 	{ "keyboard", 0x60, 0x6f, IORESOURCE_BUSY },
 	{ "dma page reg", 0x80, 0x8f, IORESOURCE_BUSY },
 	{ "pic2", 0xa0, 0xbf, IORESOURCE_BUSY },