[PATCH 3.12 087/181] mei: me: read H_CSR after asserting reset

Jiri Slaby
2014-06-30T12:06:45Z

From: Tomas Winkler <tomas.winkler@intel.com>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit c40765d919d25d2d44d99c4ce39e48808f137e1e upstream.

According the spec the host should read H_CSR again
after asserting reset H_RST to ensure that reset was
read by the firmware

Cc: stable@vger.kernel.org #3.12
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/misc/mei/hw-me.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 6cba26d9465f..aef6ec137acd 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -186,7 +186,19 @@ static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable)
dev->recvd_hw_ready = false;
mei_me_reg_write(hw, H_CSR, hcsr);

- if (dev->dev_state == MEI_DEV_POWER_DOWN)
+ /*
+ * Host reads the H_CSR once to ensure that the
+ * posted write to H_CSR completes.
+ */
+ hcsr = mei_hcsr_read(hw);
+
+ if ((hcsr & H_RST) == 0)
+ dev_warn(&dev->pdev->dev, "H_RST is not set = 0x%08X", hcsr);
+
+ if ((hcsr & H_RDY) == H_RDY)
+ dev_warn(&dev->pdev->dev, "H_RDY is not cleared 0x%08X", hcsr);
+
+ if (intr_enable == false)
mei_me_hw_reset_release(dev);

return 0;
--
2.0.0