Commit 6127b3bc authored by Juston Li's avatar Juston Li Committed by Daniele Ceraolo Spurio
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drm/i915/pxp: don't start pxp without mei_pxp bind 



pxp will not start correctly until after mei_pxp bind completes and
intel_pxp_init_hw() is called.
Wait for the bind to complete before proceeding with startup.

This fixes a race condition during bootup where we observed a small
window for pxp commands to be sent, starting pxp before mei_pxp bind
completed.

Changes since v2:
- wait for pxp_component to bind instead of returning -EAGAIN (Daniele)

Changes since v1:
- check pxp_component instead of pxp_component_added (Daniele)
- pxp_component needs tee_mutex (Daniele)
- return -EAGAIN so caller knows to retry (Daniele)

Signed-off-by: default avatarJuston Li <justonli@chromium.org>
Reviewed-by: default avatarAndrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220818174205.2412730-1-justonli@chromium.org
parent 068a0f5c

drivers/gpu/drm/i915/pxp/intel_pxp.c

+15 −0
Original line number Diff line number Diff line
@@ -176,6 +176,18 @@ static void pxp_queue_termination(struct intel_pxp *pxp) 
	spin_unlock_irq(&gt->irq_lock);

}



static bool pxp_component_bound(struct intel_pxp *pxp)

{

	bool bound = false;



	mutex_lock(&pxp->tee_mutex);

	if (pxp->pxp_component)

		bound = true;

	mutex_unlock(&pxp->tee_mutex);



	return bound;

}



/*

 * the arb session is restarted from the irq work when we receive the

 * termination completion interrupt
@@ -187,6 +199,9 @@ int intel_pxp_start(struct intel_pxp *pxp) 
	if (!intel_pxp_is_enabled(pxp))

		return -ENODEV;



	if (wait_for(pxp_component_bound(pxp), 250))

		return -ENXIO;



	mutex_lock(&pxp->arb_mutex);



	if (pxp->arb_is_valid)