vga_switcheroo: initial implementation (v15)

Many new laptops now come with 2 gpus, one to be used for low power
modes and one for gaming/on-ac applications. These GPUs are typically
wired to the laptop panel and VGA ports via a multiplexer unit which
is controlled via ACPI methods.

4 combinations of systems typically exist - with 2 ACPI methods.
Intel/ATI - Lenovo W500/T500 - use ATPX ACPI method
ATI/ATI - some ASUS - use ATPX ACPI Method
Intel/Nvidia - - use _DSM ACPI method
Nvidia/Nvidia -  - use _DSM ACPI method.

TODO:
This patch adds support for the ATPX method and initial bits
for the _DSM methods that need to written by someone with
access to the hardware.
Add a proper non-debugfs interface - need to get some proper
testing first.

v2: add power up/down support for both devices
on W500 puts i915/radeon into D3 and cuts power to radeon.

v3: redo probing methods, no DMI list, drm devices call to
register with switcheroo, it tries to find an ATPX method on
any device and once there is two devices + ATPX it inits the
switcher.

v4: ATPX msg handling using buffers - should work on more machines

v5: rearchitect after more mjg59 discussion - move ATPX handling to
    radeon driver.

v6: add file headers + initial nouveau bits (to be filled out).

v7: merge delayed switcher code.

v8: avoid suspend/resume of gpu that is off

v9: rearchitect - mjg59 is always right. - move all ATPX code to
radeon, should allow simpler DSM also proper ATRM handling

v10: add ATRM support for radeon BIOS, add mutex to lock vgasr_priv

v11: fix bug in resuming Intel for 2nd time.

v12: start fixing up nvidia code blindly.

v13: blindly guess at finishing nvidia code

v14: remove radeon audio hacks - fix up intel resume more like upstream

v15: clean up printks + remove unnecessary igd/dis pointers

mount debugfs

/sys/kernel/debug/vgaswitcheroo/switch - should exist if ATPX detected
 + 2 cards.

DIS - immediate change to discrete
IGD - immediate change to IGD
DDIS - delayed change to discrete
DIGD - delayed change to IGD
ON - turn on not in use
OFF - turn off not in use

Tested on W500 (Intel/ATI) and T500 (Intel/ATI)

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

9 files changed, 358 insertions, 6 deletions

diff --git a/drivers/gpu/drm/radeon/Makefile b/drivers/gpu/drm/radeon/Makefile
index 1cc7b937b1ea..8e62fe13e31c 100644
--- a/drivers/gpu/drm/radeon/Makefile
+++ b/drivers/gpu/drm/radeon/Makefile
@@ -54,7 +54,8 @@ radeon-y += radeon_device.o radeon_kms.o \
         radeon_cs.o radeon_bios.o radeon_benchmark.o r100.o r300.o r420.o \
         rs400.o rs600.o rs690.o rv515.o r520.o r600.o rv770.o radeon_test.o \
         r200.o radeon_legacy_tv.o r600_cs.o r600_blit.o r600_blit_shaders.o \
-        r600_blit_kms.o radeon_pm.o atombios_dp.o r600_audio.o r600_hdmi.o
+        r600_blit_kms.o radeon_pm.o atombios_dp.o r600_audio.o r600_hdmi.o \
+        radeon_atpx_handler.o
 
 radeon-$(CONFIG_COMPAT) += radeon_ioc32.o
 
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index c0356bb193e5..a5dfb1557d3e 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -118,6 +118,10 @@ struct radeon_device;
 /*
  * BIOS.
  */
+#define ATRM_BIOS_PAGE 4096
+
+bool radeon_atrm_supported(struct pci_dev *pdev);
+int radeon_atrm_get_bios_chunk(uint8_t *bios, int offset, int len);
 bool radeon_get_bios(struct radeon_device *rdev);
 
 
@@ -838,6 +842,8 @@ struct radeon_device {
         int                     audio_bits_per_sample;
         uint8_t                 audio_status_bits;
         uint8_t                 audio_category_code;
+
+        bool powered_down;
 };
 
 int radeon_device_init(struct radeon_device *rdev,
@@ -1042,6 +1048,8 @@ extern void radeon_legacy_set_clock_gating(struct radeon_device *rdev, int enabl
 extern void radeon_atom_set_clock_gating(struct radeon_device *rdev, int enable);
 extern void radeon_ttm_placement_from_domain(struct radeon_bo *rbo, u32 domain);
 extern bool radeon_ttm_bo_is_radeon_bo(struct ttm_buffer_object *bo);
+extern int radeon_resume_kms(struct drm_device *dev);
+extern int radeon_suspend_kms(struct drm_device *dev, pm_message_t state);
 
 /* r100,rv100,rs100,rv200,rs200,r200,rv250,rs300,rv280 */
 struct r100_mc_save {
diff --git a/drivers/gpu/drm/radeon/radeon_atpx_handler.c b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
new file mode 100644
index 000000000000..0ae52f19071d
--- /dev/null
+++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c
@@ -0,0 +1,258 @@
+/*
+ * Copyright (c) 2010 Red Hat Inc.
+ * Author : Dave Airlie <airlied@redhat.com>
+ *
+ * Licensed under GPLv2
+ *
+ * ATPX support for both Intel/ATI
+ */
+
+#include <linux/vga_switcheroo.h>
+#include <acpi/acpi.h>
+#include <acpi/acpi_bus.h>
+#include <linux/pci.h>
+
+#define ATPX_VERSION 0
+#define ATPX_GPU_PWR 2
+#define ATPX_MUX_SELECT 3
+
+#define ATPX_INTEGRATED 0
+#define ATPX_DISCRETE 1
+
+#define ATPX_MUX_IGD 0
+#define ATPX_MUX_DISCRETE 1
+
+static struct radeon_atpx_priv {
+        bool atpx_detected;
+        /* handle for device - and atpx */
+        acpi_handle dhandle;
+        acpi_handle atpx_handle;
+        acpi_handle atrm_handle;
+} radeon_atpx_priv;
+
+/* retrieve the ROM in 4k blocks */
+static int radeon_atrm_call(acpi_handle atrm_handle, uint8_t *bios,
+                            int offset, int len)
+{
+        acpi_status status;
+        union acpi_object atrm_arg_elements[2], *obj;
+        struct acpi_object_list atrm_arg;
+        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
+
+        atrm_arg.count = 2;
+        atrm_arg.pointer = &atrm_arg_elements[0];
+
+        atrm_arg_elements[0].type = ACPI_TYPE_INTEGER;
+        atrm_arg_elements[0].integer.value = offset;
+
+        atrm_arg_elements[1].type = ACPI_TYPE_INTEGER;
+        atrm_arg_elements[1].integer.value = len;
+
+        status = acpi_evaluate_object(atrm_handle, NULL, &atrm_arg, &buffer);
+        if (ACPI_FAILURE(status)) {
+                printk("failed to evaluate ATRM got %s\n", acpi_format_exception(status));
+                return -ENODEV;
+        }
+
+        obj = (union acpi_object *)buffer.pointer;
+        memcpy(bios+offset, obj->buffer.pointer, len);
+        kfree(buffer.pointer);
+        return len;
+}
+
+bool radeon_atrm_supported(struct pci_dev *pdev)
+{
+        /* get the discrete ROM only via ATRM */
+        if (!radeon_atpx_priv.atpx_detected)
+                return false;
+
+        if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
+                return false;
+        return true;
+}
+
+
+int radeon_atrm_get_bios_chunk(uint8_t *bios, int offset, int len)
+{
+        return radeon_atrm_call(radeon_atpx_priv.atrm_handle, bios, offset, len);
+}
+
+static int radeon_atpx_get_version(acpi_handle handle)
+{
+        acpi_status status;
+        union acpi_object atpx_arg_elements[2], *obj;
+        struct acpi_object_list atpx_arg;
+        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+        atpx_arg.count = 2;
+        atpx_arg.pointer = &atpx_arg_elements[0];
+
+        atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
+        atpx_arg_elements[0].integer.value = ATPX_VERSION;
+
+        atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
+        atpx_arg_elements[1].integer.value = ATPX_VERSION;
+
+        status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
+        if (ACPI_FAILURE(status)) {
+                printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
+                return -ENOSYS;
+        }
+        obj = (union acpi_object *)buffer.pointer;
+        if (obj && (obj->type == ACPI_TYPE_BUFFER))
+                printk(KERN_INFO "radeon atpx: version is %d\n", *((u8 *)(obj->buffer.pointer) + 2));
+        kfree(buffer.pointer);
+        return 0;
+}
+
+static int radeon_atpx_execute(acpi_handle handle, int cmd_id, u16 value)
+{
+        acpi_status status;
+        union acpi_object atpx_arg_elements[2];
+        struct acpi_object_list atpx_arg;
+        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+        uint8_t buf[4] = {0};
+
+        if (!handle)
+                return -EINVAL;
+
+        atpx_arg.count = 2;
+        atpx_arg.pointer = &atpx_arg_elements[0];
+
+        atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
+        atpx_arg_elements[0].integer.value = cmd_id;
+
+        buf[2] = value & 0xff;
+        buf[3] = (value >> 8) & 0xff;
+
+        atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
+        atpx_arg_elements[1].buffer.length = 4;
+        atpx_arg_elements[1].buffer.pointer = buf;
+
+        status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
+        if (ACPI_FAILURE(status)) {
+                printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
+                return -ENOSYS;
+        }
+        kfree(buffer.pointer);
+
+        return 0;
+}
+
+static int radeon_atpx_set_discrete_state(acpi_handle handle, int state)
+{
+        return radeon_atpx_execute(handle, ATPX_GPU_PWR, state);
+}
+
+static int radeon_atpx_switch_mux(acpi_handle handle, int mux_id)
+{
+        return radeon_atpx_execute(handle, ATPX_MUX_SELECT, mux_id);
+}
+
+
+static int radeon_atpx_switchto(enum vga_switcheroo_client_id id)
+{
+        if (id == VGA_SWITCHEROO_IGD)
+                radeon_atpx_switch_mux(radeon_atpx_priv.atpx_handle, 0);
+        else
+                radeon_atpx_switch_mux(radeon_atpx_priv.atpx_handle, 1);
+        return 0;
+}
+
+static int radeon_atpx_power_state(enum vga_switcheroo_client_id id,
+                                   enum vga_switcheroo_state state)
+{
+        /* on w500 ACPI can't change intel gpu state */
+        if (id == VGA_SWITCHEROO_IGD)
+                return 0;
+
+        radeon_atpx_set_discrete_state(radeon_atpx_priv.atpx_handle, state);
+        return 0;
+}
+
+static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
+{
+        acpi_handle dhandle, atpx_handle, atrm_handle;
+        acpi_status status;
+
+        dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
+        if (!dhandle)
+                return false;
+
+        status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
+        if (ACPI_FAILURE(status))
+                return false;
+
+        status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
+        if (ACPI_FAILURE(status))
+                return false;
+
+        radeon_atpx_priv.dhandle = dhandle;
+        radeon_atpx_priv.atpx_handle = atpx_handle;
+        radeon_atpx_priv.atrm_handle = atrm_handle;
+        return true;
+}
+
+static int radeon_atpx_init(void)
+{
+        /* set up the ATPX handle */
+
+        radeon_atpx_get_version(radeon_atpx_priv.atpx_handle);
+        return 0;
+}
+
+static int radeon_atpx_get_client_id(struct pci_dev *pdev)
+{
+        if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
+                return VGA_SWITCHEROO_IGD;
+        else
+                return VGA_SWITCHEROO_DIS;
+}
+
+static struct vga_switcheroo_handler radeon_atpx_handler = {
+        .switchto = radeon_atpx_switchto,
+        .power_state = radeon_atpx_power_state,
+        .init = radeon_atpx_init,
+        .get_client_id = radeon_atpx_get_client_id,
+};
+
+static bool radeon_atpx_detect(void)
+{
+        char acpi_method_name[255] = { 0 };
+        struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
+        struct pci_dev *pdev = NULL;
+        bool has_atpx = false;
+        int vga_count = 0;
+
+        while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
+                vga_count++;
+
+                has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
+        }
+
+        if (has_atpx && vga_count == 2) {
+                acpi_get_name(radeon_atpx_priv.atpx_handle, ACPI_FULL_PATHNAME, &buffer);
+                printk(KERN_INFO "VGA switcheroo: detected switching method %s handle\n",
+                       acpi_method_name);
+                radeon_atpx_priv.atpx_detected = true;
+                return true;
+        }
+        return false;
+}
+
+void radeon_register_atpx_handler(void)
+{
+        bool r;
+
+        /* detect if we have any ATPX + 2 VGA in the system */
+        r = radeon_atpx_detect();
+        if (!r)
+                return;
+
+        vga_switcheroo_register_handler(&radeon_atpx_handler);
+}
+
+void radeon_unregister_atpx_handler(void)
+{
+        vga_switcheroo_unregister_handler();
+}
diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index 906921740c60..a34b909485b8 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -30,6 +30,7 @@
 #include "radeon.h"
 #include "atom.h"
 
+#include <linux/vga_switcheroo.h>
 /*
  * BIOS.
  */
@@ -62,7 +63,7 @@ static bool igp_read_bios_from_vram(struct radeon_device *rdev)
                 iounmap(bios);
                 return false;
         }
-        memcpy(rdev->bios, bios, size);
+        memcpy_fromio(rdev->bios, bios, size);
         iounmap(bios);
         return true;
 }
@@ -93,6 +94,38 @@ static bool radeon_read_bios(struct radeon_device *rdev)
         return true;
 }
 
+/* ATRM is used to get the BIOS on the discrete cards in
+ * dual-gpu systems.
+ */
+static bool radeon_atrm_get_bios(struct radeon_device *rdev)
+{
+        int ret;
+        int size = 64 * 1024;
+        int i;
+
+        if (!radeon_atrm_supported(rdev->pdev))
+                return false;
+
+        rdev->bios = kmalloc(size, GFP_KERNEL);
+        if (!rdev->bios) {
+                DRM_ERROR("Unable to allocate bios\n");
+                return false;
+        }
+
+        for (i = 0; i < size / ATRM_BIOS_PAGE; i++) {
+                ret = radeon_atrm_get_bios_chunk(rdev->bios,
+                                                 (i * ATRM_BIOS_PAGE),
+                                                 ATRM_BIOS_PAGE);
+                if (ret <= 0)
+                        break;
+        }
+
+        if (i == 0 || rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) {
+                kfree(rdev->bios);
+                return false;
+        }
+        return true;
+}
 static bool r700_read_disabled_bios(struct radeon_device *rdev)
 {
         uint32_t viph_control;
@@ -388,16 +421,16 @@ static bool radeon_read_disabled_bios(struct radeon_device *rdev)
                 return legacy_read_disabled_bios(rdev);
 }
 
+
 bool radeon_get_bios(struct radeon_device *rdev)
 {
         bool r;
         uint16_t tmp;
 
-        if (rdev->flags & RADEON_IS_IGP) {
+        r = radeon_atrm_get_bios(rdev);
+        if (r == false)
                 r = igp_read_bios_from_vram(rdev);
-                if (r == false)
-                        r = radeon_read_bios(rdev);
-        } else
+        if (r == false)
                 r = radeon_read_bios(rdev);
         if (r == false) {
                 r = radeon_read_disabled_bios(rdev);
@@ -408,6 +441,7 @@ bool radeon_get_bios(struct radeon_device *rdev)
                 return false;
         }
         if (rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) {
+                printk("BIOS signature incorrect %x %x\n", rdev->bios[0], rdev->bios[1]);
                 goto free_bios;
         }
 
diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 768b1509fa03..cb8d9a1dd69c 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -30,6 +30,7 @@
 #include <drm/drm_crtc_helper.h>
 #include <drm/radeon_drm.h>
 #include <linux/vgaarb.h>
+#include <linux/vga_switcheroo.h>
 #include "radeon_reg.h"
 #include "radeon.h"
 #include "radeon_asic.h"
@@ -613,6 +614,36 @@ void radeon_check_arguments(struct radeon_device *rdev)
         }
 }
 
+static void radeon_switcheroo_set_state(struct pci_dev *pdev, enum vga_switcheroo_state state)
+{
+        struct drm_device *dev = pci_get_drvdata(pdev);
+        struct radeon_device *rdev = dev->dev_private;
+        pm_message_t pmm = { .event = PM_EVENT_SUSPEND };
+        if (state == VGA_SWITCHEROO_ON) {
+                printk(KERN_INFO "radeon: switched on\n");
+                /* don't suspend or resume card normally */
+                rdev->powered_down = false;
+                radeon_resume_kms(dev);
+        } else {
+                printk(KERN_INFO "radeon: switched off\n");
+                radeon_suspend_kms(dev, pmm);
+                /* don't suspend or resume card normally */
+                rdev->powered_down = true;
+        }
+}
+
+static bool radeon_switcheroo_can_switch(struct pci_dev *pdev)
+{
+        struct drm_device *dev = pci_get_drvdata(pdev);
+        bool can_switch;
+
+        spin_lock(&dev->count_lock);
+        can_switch = (dev->open_count == 0);
+        spin_unlock(&dev->count_lock);
+        return can_switch;
+}
+
+
 int radeon_device_init(struct radeon_device *rdev,
                        struct drm_device *ddev,
                        struct pci_dev *pdev,
@@ -692,6 +723,9 @@ int radeon_device_init(struct radeon_device *rdev,
         /* this will fail for cards that aren't VGA class devices, just
          * ignore it */
         vga_client_register(rdev->pdev, rdev, NULL, radeon_vga_set_decode);
+        vga_switcheroo_register_client(rdev->pdev,
+                                       radeon_switcheroo_set_state,
+                                       radeon_switcheroo_can_switch);
 
         r = radeon_init(rdev);
         if (r)
@@ -723,6 +757,7 @@ void radeon_device_fini(struct radeon_device *rdev)
         rdev->shutdown = true;
         radeon_fini(rdev);
         destroy_workqueue(rdev->wq);
+        vga_switcheroo_unregister_client(rdev->pdev);
         vga_client_register(rdev->pdev, NULL, NULL, NULL);
         iounmap(rdev->rmmio);
         rdev->rmmio = NULL;
@@ -746,6 +781,8 @@ int radeon_suspend_kms(struct drm_device *dev, pm_message_t state)
         }
         rdev = dev->dev_private;
 
+        if (rdev->powered_down)
+                return 0;
         /* unpin the front buffers */
         list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
                 struct radeon_framebuffer *rfb = to_radeon_framebuffer(crtc->fb);
@@ -791,6 +828,9 @@ int radeon_resume_kms(struct drm_device *dev)
 {
         struct radeon_device *rdev = dev->dev_private;
 
+        if (rdev->powered_down)
+                return 0;
+
         acquire_console_sem();
         pci_set_power_state(dev->pdev, PCI_D0);
         pci_restore_state(dev->pdev);
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c
index 8ba3de7994d4..4ab53aa163b2 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -339,6 +339,7 @@ static int __init radeon_init(void)
                 driver = &kms_driver;
                 driver->driver_features |= DRIVER_MODESET;
                 driver->num_ioctls = radeon_max_kms_ioctl;
+                radeon_register_atpx_handler();
         }
         /* if the vga console setting is enabled still
          * let modprobe override it */
@@ -348,6 +349,7 @@ static int __init radeon_init(void)
 static void __exit radeon_exit(void)
 {
         drm_exit(driver);
+        radeon_unregister_atpx_handler();
 }
 
 module_init(radeon_init);
diff --git a/drivers/gpu/drm/radeon/radeon_drv.h b/drivers/gpu/drm/radeon/radeon_drv.h
index c57ad606504d..736237195143 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.h
+++ b/drivers/gpu/drm/radeon/radeon_drv.h
@@ -455,6 +455,9 @@ extern void r600_blit_swap(struct drm_device *dev,
                            int sx, int sy, int dx, int dy,
                            int w, int h, int src_pitch, int dst_pitch, int cpp);
 
+/* atpx handler */
+void radeon_register_atpx_handler(void);
+void radeon_unregister_atpx_handler(void);
 /* Flags for stats.boxes
  */
 #define RADEON_BOX_DMA_IDLE      0x1
diff --git a/drivers/gpu/drm/radeon/radeon_fb.c b/drivers/gpu/drm/radeon/radeon_fb.c
index d71e346e9ab5..561719223988 100644
--- a/drivers/gpu/drm/radeon/radeon_fb.c
+++ b/drivers/gpu/drm/radeon/radeon_fb.c
@@ -39,6 +39,8 @@
 
 #include "drm_fb_helper.h"
 
+#include <linux/vga_switcheroo.h>
+
 struct radeon_fb_device {
         struct drm_fb_helper helper;
         struct radeon_framebuffer       *rfb;
@@ -291,6 +293,7 @@ int radeonfb_create(struct drm_device *dev,
         rfbdev->rdev = rdev;
 
         mutex_unlock(&rdev->ddev->struct_mutex);
+        vga_switcheroo_client_fb_set(rdev->ddev->pdev, info);
         return 0;
 
 out_unref:
diff --git a/drivers/gpu/drm/radeon/radeon_kms.c b/drivers/gpu/drm/radeon/radeon_kms.c
index f23b05606eb5..5db7af6b91f4 100644
--- a/drivers/gpu/drm/radeon/radeon_kms.c
+++ b/drivers/gpu/drm/radeon/radeon_kms.c
@@ -30,6 +30,8 @@
 #include "radeon.h"
 #include "radeon_drm.h"
 
+#include <linux/vga_switcheroo.h>
+
 int radeon_driver_unload_kms(struct drm_device *dev)
 {
         struct radeon_device *rdev = dev->dev_private;
@@ -136,6 +138,7 @@ int radeon_driver_firstopen_kms(struct drm_device *dev)
 
 void radeon_driver_lastclose_kms(struct drm_device *dev)
 {
+        vga_switcheroo_process_delayed_switch();
 }
 
 int radeon_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)