Merge tag 'drm-intel-fixes-2018-09-11' of git://anongit.freedesktop.o…

…rg/drm/drm-intel into drm-fixes

This contains a regression fix for video playbacks on gen 2 hardware,
a IPS timeout error suppression on Broadwell and GVT bucked with
"Most critical one is to fix KVM's mm reference when we access guest memory,
issue was raised by Linus [1], and another one with virtual opregion fix."

[1] - https://lists.freedesktop.org/archives/intel-gvt-dev/2018-August/004130.html

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180911223229.GA30328@intel.com

drivers/gpu/drm/i915/gvt/kvmgt.c

@@ -32,6 +32,7 @@
 #include <linux/device.h>
 #include <linux/mm.h>
 #include <linux/mmu_context.h>
+#include <linux/sched/mm.h>
 #include <linux/types.h>
 #include <linux/list.h>
 #include <linux/rbtree.h>
@@ -1792,16 +1793,21 @@ static int kvmgt_rw_gpa(unsigned long handle, unsigned long gpa,
 	info = (struct kvmgt_guest_info *)handle;
 	kvm = info->kvm;
 
-	if (kthread)
+	if (kthread) {
+		if (!mmget_not_zero(kvm->mm))
+			return -EFAULT;
 		use_mm(kvm->mm);
+	}
 
 	idx = srcu_read_lock(&kvm->srcu);
 	ret = write ? kvm_write_guest(kvm, gpa, buf, len) :
 		      kvm_read_guest(kvm, gpa, buf, len);
 	srcu_read_unlock(&kvm->srcu, idx);
 
-	if (kthread)
+	if (kthread) {
 		unuse_mm(kvm->mm);
+		mmput(kvm->mm);
+	}
 
 	return ret;
 }

drivers/gpu/drm/i915/gvt/opregion.c

@@ -42,8 +42,6 @@
 #define DEVICE_TYPE_EFP3   0x20
 #define DEVICE_TYPE_EFP4   0x10
 
-#define DEV_SIZE	38
-
 struct opregion_header {
 	u8 signature[16];
 	u32 size;
@@ -63,6 +61,10 @@ struct bdb_data_header {
 	u16 size; /* data size */
 } __packed;
 
+/* For supporting windows guest with opregion, here hardcode the emulated
+ * bdb header version as '186', and the corresponding child_device_config
+ * length should be '33' but not '38'.
+ */
 struct efp_child_device_config {
 	u16 handle;
 	u16 device_type;
@@ -109,12 +111,6 @@ struct efp_child_device_config {
 	u8 mipi_bridge_type; /* 171 */
 	u16 device_class_ext;
 	u8 dvo_function;
-	u8 dp_usb_type_c:1; /* 195 */
-	u8 skip6:7;
-	u8 dp_usb_type_c_2x_gpio_index; /* 195 */
-	u16 dp_usb_type_c_2x_gpio_pin; /* 195 */
-	u8 iboost_dp:4; /* 196 */
-	u8 iboost_hdmi:4; /* 196 */
 } __packed;
 
 struct vbt {
@@ -155,7 +151,7 @@ static void virt_vbt_generation(struct vbt *v)
 	v->header.bdb_offset = offsetof(struct vbt, bdb_header);
 
 	strcpy(&v->bdb_header.signature[0], "BIOS_DATA_BLOCK");
-	v->bdb_header.version = 186; /* child_dev_size = 38 */
+	v->bdb_header.version = 186; /* child_dev_size = 33 */
 	v->bdb_header.header_size = sizeof(v->bdb_header);
 
 	v->bdb_header.bdb_size = sizeof(struct vbt) - sizeof(struct vbt_header)
@@ -169,11 +165,13 @@ static void virt_vbt_generation(struct vbt *v)
 
 	/* child device */
 	num_child = 4; /* each port has one child */
+	v->general_definitions.child_dev_size =
+		sizeof(struct efp_child_device_config);
 	v->general_definitions_header.id = BDB_GENERAL_DEFINITIONS;
 	/* size will include child devices */
 	v->general_definitions_header.size =
-		sizeof(struct bdb_general_definitions) + num_child * DEV_SIZE;
-	v->general_definitions.child_dev_size = DEV_SIZE;
+		sizeof(struct bdb_general_definitions) +
+			num_child * v->general_definitions.child_dev_size;
 
 	/* portA */
 	v->child0.handle = DEVICE_TYPE_EFP1;

drivers/gpu/drm/i915/intel_display.c

@@ -5079,10 +5079,14 @@ void hsw_disable_ips(const struct intel_crtc_state *crtc_state)
 		mutex_lock(&dev_priv->pcu_lock);
 		WARN_ON(sandybridge_pcode_write(dev_priv, DISPLAY_IPS_CONTROL, 0));
 		mutex_unlock(&dev_priv->pcu_lock);
-		/* wait for pcode to finish disabling IPS, which may take up to 42ms */
+		/*
+		 * Wait for PCODE to finish disabling IPS. The BSpec specified
+		 * 42ms timeout value leads to occasional timeouts so use 100ms
+		 * instead.
+		 */
 		if (intel_wait_for_register(dev_priv,
 					    IPS_CTL, IPS_ENABLE, 0,
-					    42))
+					    100))
 			DRM_ERROR("Timed out waiting for IPS disable\n");
 	} else {
 		I915_WRITE(IPS_CTL, 0);