| From | Jiri Slaby <> | Subject | [PATCH 3.12 088/181] mei: me: fix hw ready reset flow | Date | Mon, 30 Jun 2014 13:51:49 +0200 |
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From: Tomas Winkler <tomas.winkler@intel.com>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
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.
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, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/misc/mei/hw-me.c b/drivers/misc/mei/hw-me.c index aef6ec137acd..e513354f20a7 100644 --- 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(struct mei_device *dev) 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. @@ -214,6 +217,7 @@ static int mei_me_hw_reset(struct mei_device *dev, bool intr_enable) 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); } @@ -506,19 +510,15 @@ irqreturn_t mei_me_irq_thread_handler(int irq, void *dev_id) /* 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); - - mutex_unlock(&dev->device_lock); - return IRQ_HANDLED; } else { - dev_dbg(&dev->pdev->dev, "Reset Completed.\n"); - mei_me_hw_reset_release(dev); - mutex_unlock(&dev->device_lock); - return IRQ_HANDLED; + dev_dbg(&dev->pdev->dev, "Spurious Interrupt\n"); } + goto end; } /* check slots available for reading */ slots = mei_count_full_read_slots(dev); -- 2.0.0
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