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Commit a0bdcbb5 authored by Shivaraj Shetty's avatar Shivaraj Shetty
Browse files

msm: mdss: protect iommu refcount with mutex for mdp3 



On mdp3 targets iommu refcount is not properly protected
by mutex lock. This is causing iommu to be detached while
hardware is fetching the data from the iommu mapped
address leading to SNOC errors. Add mutex lock while
using the iommu refcounts to fix the issue.

Change-Id: Ife59791b08b123f6b60d3ffa6d8061839244934c
Signed-off-by: default avatarShivaraj Shetty <shivaraj@codeaurora.org>
parent 32829884

drivers/video/msm/mdss/mdp3.c

+8 −6
Original line number Diff line number Diff line
@@ -726,11 +726,9 @@ int mdp3_iommu_attach(int context) 
	if (context >= MDP3_IOMMU_CTX_MAX)

		return -EINVAL;



	mutex_lock(&mdp3_res->iommu_lock);

	context_map = mdp3_res->iommu_contexts + context;

	if (context_map->attached) {

		pr_warn("mdp iommu already attached\n");

		mutex_unlock(&mdp3_res->iommu_lock);

		return 0;

	}
@@ -743,7 +741,6 @@ int mdp3_iommu_attach(int context) 
	}



	context_map->attached = true;

	mutex_unlock(&mdp3_res->iommu_lock);

	return 0;

}
@@ -756,11 +753,9 @@ int mdp3_iommu_dettach(int context) 
		context >= MDP3_IOMMU_CTX_MAX)

		return -EINVAL;



	mutex_lock(&mdp3_res->iommu_lock);

	context_map = mdp3_res->iommu_contexts + context;

	if (!context_map->attached) {

		pr_warn("mdp iommu not attached\n");

		mutex_unlock(&mdp3_res->iommu_lock);

		return 0;

	}
@@ -768,7 +763,6 @@ int mdp3_iommu_dettach(int context) 
	iommu_detach_device(domain_map->domain, context_map->ctx);

	context_map->attached = false;



	mutex_unlock(&mdp3_res->iommu_lock);

	return 0;

}
@@ -966,7 +960,11 @@ static void mdp3_res_deinit(void) 


	mdp3_hw = &mdp3_res->mdp3_hw;

	mdp3_bus_scale_unregister();



	mutex_lock(&mdp3_res->iommu_lock);

	mdp3_iommu_dettach(MDP3_IOMMU_CTX_MDP_0);

	mutex_unlock(&mdp3_res->iommu_lock);



	mdp3_iommu_deinit();



	if (!IS_ERR_OR_NULL(mdp3_res->ion_client))
@@ -1366,6 +1364,7 @@ int mdp3_iommu_enable() 
{

	int i, rc = 0;



	mutex_lock(&mdp3_res->iommu_lock);

	if (mdp3_res->iommu_ref_cnt == 0) {

		for (i = 0; i < MDP3_IOMMU_CTX_MAX; i++) {

			rc = mdp3_iommu_attach(i);
@@ -1379,6 +1378,7 @@ int mdp3_iommu_enable() 


	if (!rc)

		mdp3_res->iommu_ref_cnt++;

	mutex_unlock(&mdp3_res->iommu_lock);



	return rc;

}
@@ -1387,6 +1387,7 @@ int mdp3_iommu_disable() 
{

	int i, rc = 0;



	mutex_lock(&mdp3_res->iommu_lock);

	if (mdp3_res->iommu_ref_cnt) {

		mdp3_res->iommu_ref_cnt--;

		if (mdp3_res->iommu_ref_cnt == 0) {
@@ -1396,6 +1397,7 @@ int mdp3_iommu_disable() 
	} else {

		pr_err("iommu ref count unbalanced\n");

	}

	mutex_unlock(&mdp3_res->iommu_lock);



	return rc;

}