| From b04ada92ffaabb868497a1fce8e4f6bf74e5488f Mon Sep 17 00:00:00 2001 |
| From: Tomas Winkler <tomas.winkler@intel.com> |
| Date: Mon, 12 May 2014 12:19:39 +0300 |
| Subject: mei: me: fix hw ready reset flow |
| |
| From: Tomas Winkler <tomas.winkler@intel.com> |
| |
| commit b04ada92ffaabb868497a1fce8e4f6bf74e5488f upstream. |
| |
| We cleared H_RST for H_CSR on spurious interrupt generated when ME_RDY |
| while cleared and not while ME_RDY is set. The spurious interrupt |
| is not delivered on all platforms in this case the |
| driver may fail to initialize. |
| |
| 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> |
| |
| --- |
| drivers/misc/mei/hw-me.c | 9 ++++++--- |
| 1 file changed, 6 insertions(+), 3 deletions(-) |
| |
| --- a/drivers/misc/mei/hw-me.c |
| +++ b/drivers/misc/mei/hw-me.c |
| @@ -164,6 +164,9 @@ static void mei_me_hw_reset_release(stru |
| hcsr |= H_IG; |
| hcsr &= ~H_RST; |
| mei_hcsr_set(hw, hcsr); |
| + |
| + /* complete this write before we set host ready on another CPU */ |
| + mmiowb(); |
| } |
| /** |
| * mei_me_hw_reset - resets fw via mei csr register. |
| @@ -201,6 +204,7 @@ static int mei_me_hw_reset(struct mei_de |
| static void mei_me_host_set_ready(struct mei_device *dev) |
| { |
| struct mei_me_hw *hw = to_me_hw(dev); |
| + hw->host_hw_state = mei_hcsr_read(hw); |
| hw->host_hw_state |= H_IE | H_IG | H_RDY; |
| mei_hcsr_set(hw, hw->host_hw_state); |
| } |
| @@ -491,14 +495,13 @@ irqreturn_t mei_me_irq_thread_handler(in |
| /* check if we need to start the dev */ |
| if (!mei_host_is_ready(dev)) { |
| if (mei_hw_is_ready(dev)) { |
| + mei_me_hw_reset_release(dev); |
| dev_dbg(&dev->pdev->dev, "we need to start the dev.\n"); |
| |
| dev->recvd_hw_ready = true; |
| wake_up_interruptible(&dev->wait_hw_ready); |
| } else { |
| - |
| - dev_dbg(&dev->pdev->dev, "Reset Completed.\n"); |
| - mei_me_hw_reset_release(dev); |
| + dev_dbg(&dev->pdev->dev, "Spurious Interrupt\n"); |
| } |
| goto end; |
| } |