From: Dave Jones <davej@redhat.com>
Date: Wed, 1 Jun 2005 02:03:51 +0000 (-0700)
Subject: [CPUFREQ] Longhaul: Magic timer frobbing.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=1174631418fbb2c0c6946081b0b7d391f5d92861;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

[CPUFREQ] Longhaul: Magic timer frobbing.

As mandated by the spec, disable timer around transitions.

From code by : Ken Staton <ken_staton@agilent.com
Signed-off-by: Dave Jones <davej@redhat.com>
---

diff --git a/arch/i386/kernel/cpu/cpufreq/longhaul.c b/arch/i386/kernel/cpu/cpufreq/longhaul.c
index 8ea545e35b3a..48899f0956f7 100644
--- a/arch/i386/kernel/cpu/cpufreq/longhaul.c
+++ b/arch/i386/kernel/cpu/cpufreq/longhaul.c
@@ -120,9 +120,10 @@ static int longhaul_get_cpu_mult(void)
 static void do_powersaver(union msr_longhaul *longhaul,
 			unsigned int clock_ratio_index)
 {
-	int version;
-	unsigned long flags;
 	struct pci_dev *dev;
+	unsigned long flags;
+	unsigned int tmp_mask;
+	int version;
 	int i;
 	u16 pci_cmd;
 	u16 cmd_state[64];
@@ -163,6 +164,10 @@ static void do_powersaver(union msr_longhaul *longhaul,
 		}
 	} while (dev != NULL);
 
+	tmp_mask=inb(0x21);	/* works on C3. save mask. */
+	outb(0xFE,0x21);	/* TMR0 only */
+	outb(0xFF,0x80);	/* delay */
+
 	local_irq_enable();
 
 	__hlt();
@@ -171,6 +176,8 @@ static void do_powersaver(union msr_longhaul *longhaul,
 
 	local_irq_disable();
 
+	outb(tmp_mask,0x21);	/* restore mask */
+
 	/* restore pci bus master state for all devices */
 	dev = NULL;
 	i = 0;