mei: me: read H_CSR after asserting reset

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
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>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c
index 031efcfed39e..016ad88a2887 100644
--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -206,6 +206,18 @@ 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);
 
+        /*
+         * 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);