Re: [PATCH 3.11-stable] Thermal: x86_pkg_temp: change spin lock

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 10/24/2013 07:09 AM, Jonghwan Choi wrote:
From: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>

This patch looks like it should be in the 3.11-stable tree, should we apply
it?
We can. But I only had only one occurrence of this issue even on buggy platform in couple of months.
So chances of occurring is low. But is a bug.

Thanks,
Srinivas
------------------

From: "Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>"

commit 7bed1b3caaedd5918f0820b29f3b7a2ddc812922 upstream

x86_pkg_temp receives thermal notifications via a callback from a
therm_throt driver, where thermal interrupts are processed.
This callback is pkg_temp_thermal_platform_thermal_notify. Here to
avoid multiple interrupts from cores in a package, we disable the
source and also set a variable to avoid scheduling delayed work function.
This variable is protected via spin_lock_irqsave. On one buggy platform,
we still receiving interrupts even if the source is disabled. This
can cause deadlock/lockdep warning, when interrupt is generated while under
spinlock in work function.
Change spin_lock to spin_lock_irqsave and spin_unlock to
spin_unlock_irqrestore as the data it is trying to protect can also
be modified in a notification call called from interrupt handler.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Signed-off-by: Zhang Rui <rui.zhang@xxxxxxxxx>
Signed-off-by: Jonghwan Choi <jhbird.choi@xxxxxxxxxxx>
---
  drivers/thermal/x86_pkg_temp_thermal.c | 14 ++++++++------
  1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/thermal/x86_pkg_temp_thermal.c b/drivers/thermal/x86_pkg_temp_thermal.c
index f36950e..7722cb9 100644
--- a/drivers/thermal/x86_pkg_temp_thermal.c
+++ b/drivers/thermal/x86_pkg_temp_thermal.c
@@ -316,18 +316,19 @@ static void pkg_temp_thermal_threshold_work_fn(struct work_struct *work)
  	int phy_id = topology_physical_package_id(cpu);
  	struct phy_dev_entry *phdev = pkg_temp_thermal_get_phy_entry(cpu);
  	bool notify = false;
+	unsigned long flags;
if (!phdev)
  		return;
- spin_lock(&pkg_work_lock);
+	spin_lock_irqsave(&pkg_work_lock, flags);
  	++pkg_work_cnt;
  	if (unlikely(phy_id > max_phy_id)) {
-		spin_unlock(&pkg_work_lock);
+		spin_unlock_irqrestore(&pkg_work_lock, flags);
  		return;
  	}
  	pkg_work_scheduled[phy_id] = 0;
-	spin_unlock(&pkg_work_lock);
+	spin_unlock_irqrestore(&pkg_work_lock, flags);
enable_pkg_thres_interrupt();
  	rdmsrl(MSR_IA32_PACKAGE_THERM_STATUS, msr_val);
@@ -397,6 +398,7 @@ static int pkg_temp_thermal_device_add(unsigned int cpu)
  	int thres_count;
  	u32 eax, ebx, ecx, edx;
  	u8 *temp;
+	unsigned long flags;
cpuid(6, &eax, &ebx, &ecx, &edx);
  	thres_count = ebx & 0x07;
@@ -420,19 +422,19 @@ static int pkg_temp_thermal_device_add(unsigned int cpu)
  		goto err_ret_unlock;
  	}
- spin_lock(&pkg_work_lock);
+	spin_lock_irqsave(&pkg_work_lock, flags);
  	if (topology_physical_package_id(cpu) > max_phy_id)
  		max_phy_id = topology_physical_package_id(cpu);
  	temp = krealloc(pkg_work_scheduled,
  			(max_phy_id+1) * sizeof(u8), GFP_ATOMIC);
  	if (!temp) {
-		spin_unlock(&pkg_work_lock);
+		spin_unlock_irqrestore(&pkg_work_lock, flags);
  		err = -ENOMEM;
  		goto err_ret_free;
  	}
  	pkg_work_scheduled = temp;
  	pkg_work_scheduled[topology_physical_package_id(cpu)] = 0;
-	spin_unlock(&pkg_work_lock);
+	spin_unlock_irqrestore(&pkg_work_lock, flags);
phy_dev_entry->phys_proc_id = topology_physical_package_id(cpu);
  	phy_dev_entry->first_cpu = cpu;

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]