From eceab272fb895148f6293b5c0644fc2dd36d3aff Mon Sep 17 00:00:00 2001
From: Jesse Barnes <jbarnes@virtuousgeek.org>
Date: Thu, 23 Sep 2010 23:49:29 +0200
Subject: [PATCH] IPS driver: verify BIOS provided limits
They're optional. If not present or sane, we should use the CPU
defaults.
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
---
drivers/platform/x86/intel_ips.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
diff --git a/drivers/platform/x86/intel_ips.c b/drivers/platform/x86/intel_ips.c
index 71d04ef47b8c..c402cc417108 100644
--- a/drivers/platform/x86/intel_ips.c
+++ b/drivers/platform/x86/intel_ips.c
@@ -664,6 +664,27 @@ static bool mch_exceeded(struct ips_driver *ips)
return ret;
}
+/**
+ * verify_limits - verify BIOS provided limits
+ * @ips: IPS structure
+ *
+ * BIOS can optionally provide non-default limits for power and temp. Check
+ * them here and use the defaults if the BIOS values are not provided or
+ * are otherwise unusable.
+ */
+static void verify_limits(struct ips_driver *ips)
+{
+ if (ips->mcp_power_limit < ips->limits->mcp_power_limit ||
+ ips->mcp_power_limit > 35000)
+ ips->mcp_power_limit = ips->limits->mcp_power_limit;
+
+ if (ips->mcp_temp_limit < ips->limits->core_temp_limit ||
+ ips->mcp_temp_limit < ips->limits->mch_temp_limit ||
+ ips->mcp_temp_limit > 150)
+ ips->mcp_temp_limit = min(ips->limits->core_temp_limit,
+ ips->limits->mch_temp_limit);
+}
+
/**
* update_turbo_limits - get various limits & settings from regs
* @ips: IPS driver struct
@@ -688,6 +709,7 @@ static void update_turbo_limits(struct ips_driver *ips)
ips->mcp_temp_limit = thm_readw(THM_PTL);
ips->mcp_power_limit = thm_readw(THM_MPPC);
+ verify_limits(ips);
/* Ignore BIOS CPU vs GPU pref */
}
@@ -1156,6 +1178,7 @@ static irqreturn_t ips_irq_handler(int irq, void *arg)
STS_PTL_SHIFT;
ips->mcp_power_limit = (tc1 & STS_PPL_MASK) >>
STS_PPL_SHIFT;
+ verify_limits(ips);
spin_unlock(&ips->turbo_status_lock);
thm_writeb(THM_SEC, SEC_ACK);