[coreboot-gerrit] Patch set updated for coreboot: 72380e4 haswell: Remove limit on package C-state

Stefan Reinauer (stefan.reinauer@coreboot.org) gerrit at coreboot.org
Wed Nov 20 01:51:22 CET 2013


Stefan Reinauer (stefan.reinauer at coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/4163

-gerrit

commit 72380e40ed9edbcd4cf67a8188c663afe567cb06
Author: Duncan Laurie <dlaurie at chromium.org>
Date:   Tue May 7 13:19:56 2013 -0700

    haswell: Remove limit on package C-state
    
    With the XHCI controller enabled we no longer hang the
    system when dropping into a package C-state so remove
    the code that was disabling it.
    
    Change-Id: Icd60488fd2506dac04fb6ec96a77bec265b10d8c
    Signed-off-by: Duncan Laurie <dlaurie at chromium.org>
    Reviewed-on: https://gerrit.chromium.org/gerrit/50355
    Reviewed-by: Aaron Durbin <adurbin at chromium.org>
---
 src/cpu/intel/haswell/haswell_init.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/src/cpu/intel/haswell/haswell_init.c b/src/cpu/intel/haswell/haswell_init.c
index 071135c..b2e6eaf 100644
--- a/src/cpu/intel/haswell/haswell_init.c
+++ b/src/cpu/intel/haswell/haswell_init.c
@@ -426,10 +426,7 @@ static void configure_c_states(void)
 	msr.lo |= (1 << 26);	// C1 Auto Demotion Enable
 	msr.lo |= (1 << 25);	// C3 Auto Demotion Enable
 	msr.lo &= ~(1 << 10);	// Disable IO MWAIT redirection
-	msr.lo &= ~(0xf);	// Clear deepest package c-state
-	/* FIXME: The deepest package c-state is set to C0/C1 to work around
-	 * platform instability when package C3 or deeper c-states are used. */
-	msr.lo |= 0;		// Deepeset package c-state is C0/C1.
+	/* The deepest package c-state defaults to factory-configured value. */
 	wrmsr(MSR_PMG_CST_CONFIG_CONTROL, msr);
 
 	msr = rdmsr(MSR_PMG_IO_CAPTURE_BASE);



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