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Commit b04ada92 authored by Tomas Winkler's avatar Tomas Winkler Committed by Greg Kroah-Hartman
Browse files

mei: me: fix hw ready reset flow 



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
Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 84b3294a

drivers/misc/mei/hw-me.c

+6 −3
Original line number Diff line number Diff line
@@ -181,6 +181,9 @@ 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.
@@ -218,6 +221,7 @@ 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);

}
@@ -646,14 +650,13 @@ 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);

		} 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;

	}