[PATCH 3.18 126/183] mei: clean reset bit before reset

Greg Kroah-Hartman
2015-01-25T18:36:15Z

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

commit b13a65ef190e488e2761d65bdd2e1fe8a3a125f5 upstream.

H_RST bit in H_CSR register 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 we need to clean
H_RST bit to start a successful reset sequence.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/misc/mei/hw-me.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

--- a/drivers/misc/mei/hw-me.c
+++ b/drivers/misc/mei/hw-me.c
@@ -234,6 +234,18 @@ static int mei_me_hw_reset(struct mei_de
struct mei_me_hw *hw = to_me_hw(dev);
u32 hcsr = mei_hcsr_read(hw);

+ /* 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
+ * we need to clean H_RST bit to start a successful reset sequence.
+ */
+ if ((hcsr & H_RST) == H_RST) {
+ dev_warn(dev->dev, "H_RST is set = 0x%08X", hcsr);
+ hcsr &= ~H_RST;
+ mei_me_reg_write(hw, H_CSR, hcsr);
+ hcsr = mei_hcsr_read(hw);
+ }
+
hcsr |= H_RST | H_IG | H_IS;

if (intr_enable)