linux-kernel - [char-misc-next 7/9] mei: me: d0i3: exit d0i3 on driver start and enter it on stop

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Date:	Sun,  2 Aug 2015 22:20:56 +0300
From:	Tomas Winkler <tomas.winkler@...el.com>
To:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:	arnd@...db.de, Alexander Usyskin <alexander.usyskin@...el.com>,
	linux-kernel@...r.kernel.org,
	Tomas Winkler <tomas.winkler@...el.com>
Subject: [char-misc-next 7/9] mei: me: d0i3: exit d0i3 on driver start and enter it on stop

From: Alexander Usyskin <alexander.usyskin@...el.com>

A BIOS may put the device in d0i3 on platform initialization so it won’t
consume power even if the driver is not present, in turn the driver has
to wake up the devices on load in order to perform the initialization
sequence and move it back to low power state on driver remove.

Signed-off-by: Alexander Usyskin <alexander.usyskin@...el.com>
Signed-off-by: Tomas Winkler <tomas.winkler@...el.com>
---
 drivers/misc/mei/hw-me.c | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 448f28133489..65511d39d89b 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -213,12 +213,17 @@ static void mei_me_hw_config(struct mei_device *dev)
 	hcsr = mei_hcsr_read(dev);
 	dev->hbuf_depth = (hcsr & H_CBD) >> 24;
 
-	hw->pg_state = MEI_PG_OFF;
-
 	reg = 0;
 	pci_read_config_dword(pdev, PCI_CFG_HFS_1, &reg);
 	hw->d0i3_supported =
 		((reg & PCI_CFG_HFS_1_D0I3_MSK) == PCI_CFG_HFS_1_D0I3_MSK);
+
+	hw->pg_state = MEI_PG_OFF;
+	if (hw->d0i3_supported) {
+		reg = mei_me_d0i3c_read(dev);
+		if (reg & H_D0I3C_I3)
+			hw->pg_state = MEI_PG_ON;
+	}
 }
 
 /**
@@ -1037,12 +1042,24 @@ int mei_me_pg_exit_sync(struct mei_device *dev)
  * @dev: the device structure
  * @intr_enable: if interrupt should be enabled after reset.
  *
- * Return: always 0
+ * Return: 0 on success an error code otherwise
  */
 static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
 {
-	u32 hcsr = mei_hcsr_read(dev);
+	struct mei_me_hw *hw = to_me_hw(dev);
+	int ret;
+	u32 hcsr;
+
+	if (intr_enable) {
+		mei_me_intr_enable(dev);
+		if (hw->d0i3_supported) {
+			ret = mei_me_d0i3_exit_sync(dev);
+			if (ret)
+				return ret;
+		}
+	}
 
+	hcsr = mei_hcsr_read(dev);
 	/* H_RST may be found lit before reset is started,
 	 * for example if preceding reset flow hasn't completed.
 	 * In that case asserting H_RST will be ignored, therefore
@@ -1057,9 +1074,7 @@ static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
 
 	hcsr |= H_RST | H_IG | H_CSR_IS_MASK;
 
-	if (intr_enable)
-		hcsr |= H_CSR_IE_MASK;
-	else
+	if (!intr_enable)
 		hcsr &= ~H_CSR_IE_MASK;
 
 	dev->recvd_hw_ready = false;
@@ -1077,9 +1092,14 @@ static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
 	if ((hcsr & H_RDY) == H_RDY)
 		dev_warn(dev->dev, "H_RDY is not cleared 0x%08X", hcsr);
 
-	if (intr_enable == false)
+	if (!intr_enable) {
 		mei_me_hw_reset_release(dev);
-
+		if (hw->d0i3_supported) {
+			ret = mei_me_d0i3_enter(dev);
+			if (ret)
+				return ret;
+		}
+	}
 	return 0;
 }
 
-- 
2.4.3

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