drm/msm/mdp: Detach iommu in mdp4_destroy

attach_dev gets called in mdp4_kms_init, but there is no corresponding
detach_dev called in the error path or in the kms driver unload path.

Detach and destroy mmu in mdp4_destroy.
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/mdp/mdp4/mdp4_kms.c

@@ -179,9 +179,20 @@ static long mdp4_round_pixclk(struct msm_kms *kms, unsigned long rate,
 	}
 }
 
+static const char * const iommu_ports[] = {
+	"mdp_port0_cb0", "mdp_port1_cb0",
+};
+
 static void mdp4_destroy(struct msm_kms *kms)
 {
 	struct mdp4_kms *mdp4_kms = to_mdp4_kms(to_mdp_kms(kms));
+	struct msm_mmu *mmu = mdp4_kms->mmu;
+
+	if (mmu) {
+		mmu->funcs->detach(mmu, iommu_ports, ARRAY_SIZE(iommu_ports));
+		mmu->funcs->destroy(mmu);
+	}
+
 	if (mdp4_kms->blank_cursor_iova)
 		msm_gem_put_iova(mdp4_kms->blank_cursor_bo, mdp4_kms->id);
 	if (mdp4_kms->blank_cursor_bo)
@@ -446,10 +457,6 @@ static int modeset_init(struct mdp4_kms *mdp4_kms)
 	return ret;
 }
 
-static const char *iommu_ports[] = {
-		"mdp_port0_cb0", "mdp_port1_cb0",
-};
-
 struct msm_kms *mdp4_kms_init(struct drm_device *dev)
 {
 	struct platform_device *pdev = dev->platformdev;
@@ -554,6 +561,8 @@ struct msm_kms *mdp4_kms_init(struct drm_device *dev)
 				ARRAY_SIZE(iommu_ports));
 		if (ret)
 			goto fail;
+
+		mdp4_kms->mmu = mmu;
 	} else {
 		dev_info(dev->dev, "no iommu, fallback to phys "
 				"contig buffers for scanout\n");

drivers/gpu/drm/msm/mdp/mdp4/mdp4_kms.h

@@ -45,6 +45,7 @@ struct mdp4_kms {
 	struct clk *pclk;
 	struct clk *lut_clk;
 	struct clk *axi_clk;
+	struct msm_mmu *mmu;
 
 	struct mdp_irq error_handler;