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authorTomas Winkler <tomas.winkler@intel.com>2013-03-10 13:56:07 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-03-15 11:18:08 -0700
commit68f8ea184bf7a552b59a38c4b0c7dc243822d2d5 (patch)
treea116d50a78d748dabe04e3d45e07adf25e2ef0e0
parent7cb035d9e619a8d20f5d3b9791f8cb5160d19e70 (diff)
mei: ME hardware reset needs to be synchronized
This fixes failure during initialization on Lynx Point LP devices. ME driver needs to release the device from the reset only after the FW has completed its flow and indicated it by delivering an interrupt to the host. This is the correct behavior for all the ME devices yet the the previous versions are less susceptive to the implementation that ignored FW reset completion indication. We add mei_me_hw_reset_release function which is called after reset from the interrupt thread or directly from mei_reset during power down. Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/misc/mei/hw-me.c29
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 45ea7185c003..642c6223fa6c 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -152,6 +152,20 @@ static void mei_me_intr_disable(struct mei_device *dev)
}
/**
+ * mei_me_hw_reset_release - release device from the reset
+ *
+ * @dev: the device structure
+ */
+static void mei_me_hw_reset_release(struct mei_device *dev)
+{
+ struct mei_me_hw *hw = to_me_hw(dev);
+ u32 hcsr = mei_hcsr_read(hw);
+
+ hcsr |= H_IG;
+ hcsr &= ~H_RST;
+ mei_hcsr_set(hw, hcsr);
+}
+/**
* mei_me_hw_reset - resets fw via mei csr register.
*
* @dev: the device structure
@@ -169,18 +183,14 @@ static void mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
if (intr_enable)
hcsr |= H_IE;
else
- hcsr &= ~H_IE;
-
- mei_hcsr_set(hw, hcsr);
-
- hcsr = mei_hcsr_read(hw) | H_IG;
- hcsr &= ~H_RST;
+ hcsr |= ~H_IE;
mei_hcsr_set(hw, hcsr);
- hcsr = mei_hcsr_read(hw);
+ if (dev->dev_state == MEI_DEV_POWER_DOWN)
+ mei_me_hw_reset_release(dev);
- dev_dbg(&dev->pdev->dev, "current HCSR = 0x%08x.\n", hcsr);
+ dev_dbg(&dev->pdev->dev, "current HCSR = 0x%08x.\n", mei_hcsr_read(hw));
}
/**
@@ -466,7 +476,8 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id)
mutex_unlock(&dev->device_lock);
return IRQ_HANDLED;
} else {
- dev_dbg(&dev->pdev->dev, "FW not ready.\n");
+ dev_dbg(&dev->pdev->dev, "Reset Completed.\n");
+ mei_me_hw_reset_release(dev);
mutex_unlock(&dev->device_lock);
return IRQ_HANDLED;
}