vga_switcheroo: Use VGA_SWITCHEROO_UNKNOWN_ID instead of -1

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index a7870d2..9896305 100644 (file)
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c
@@ -84,9 +84,9 @@
  * @fb_info: framebuffer to which console is remapped on switching
  * @pwr_state: current power state
  * @ops: client callbacks
- * @id: client identifier, see enum vga_switcheroo_client_id.
- *     Determining the id requires the handler, so GPUs are initially
- *     assigned -1 and later given their true id in vga_switcheroo_enable()
+ * @id: client identifier. Determining the id requires the handler,
+ *     so gpus are initially assigned VGA_SWITCHEROO_UNKNOWN_ID
+ *     and later given their true id in vga_switcheroo_enable()
  * @active: whether the outputs are currently switched to this client
  * @driver_power_control: whether power state is controlled by the driver's
  *     runtime pm. If true, writing ON and OFF to the vga_switcheroo debugfs
@@ -145,7 +145,8 @@ struct vgasr_priv {
 
 #define ID_BIT_AUDIO           0x100
 #define client_is_audio(c)     ((c)->id & ID_BIT_AUDIO)
-#define client_is_vga(c)       ((c)->id == -1 || !client_is_audio(c))
+#define client_is_vga(c)       ((c)->id == VGA_SWITCHEROO_UNKNOWN_ID || \
+                                !client_is_audio(c))
 #define client_id(c)           ((c)->id & ~ID_BIT_AUDIO)
 
 static int vga_switcheroo_debugfs_init(struct vgasr_priv *priv);
@@ -173,7 +174,7 @@ static void vga_switcheroo_enable(void)
                vgasr_priv.handler->init();
 
        list_for_each_entry(client, &vgasr_priv.clients, list) {
-               if (client->id != -1)
+               if (client->id != VGA_SWITCHEROO_UNKNOWN_ID)
                        continue;
                ret = vgasr_priv.handler->get_client_id(client->pdev);
                if (ret < 0)
@@ -277,7 +278,7 @@ int vga_switcheroo_register_client(struct pci_dev *pdev,
                                   const struct vga_switcheroo_client_ops *ops,
                                   bool driver_power_control)
 {
-       return register_client(pdev, ops, -1,
+       return register_client(pdev, ops, VGA_SWITCHEROO_UNKNOWN_ID,
                               pdev == vga_default_device(),
                               driver_power_control);
 }
@@ -583,7 +584,7 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
        int ret;
        bool delay = false, can_switch;
        bool just_mux = false;
-       int client_id = -1;
+       int client_id = VGA_SWITCHEROO_UNKNOWN_ID;
        struct vga_switcheroo_client *client = NULL;
 
        if (cnt > 63)
@@ -652,7 +653,7 @@ vga_switcheroo_debugfs_write(struct file *filp, const char __user *ubuf,
                client_id = VGA_SWITCHEROO_DIS;
        }
 
-       if (client_id == -1)
+       if (client_id == VGA_SWITCHEROO_UNKNOWN_ID)
                goto out;
        client = find_client_from_id(&vgasr_priv.clients, client_id);
        if (!client)

diff --git a/include/linux/vga_switcheroo.h b/include/linux/vga_switcheroo.h
index e636617..88909a8 100644 (file)
--- a/include/linux/vga_switcheroo.h
+++ b/include/linux/vga_switcheroo.h
@@ -59,6 +59,9 @@ enum vga_switcheroo_state {
 
 /**
  * enum vga_switcheroo_client_id - client identifier
+ * @VGA_SWITCHEROO_UNKNOWN_ID: initial identifier assigned to vga clients.
+ *     Determining the id requires the handler, so GPUs are given their
+ *     true id in a delayed fashion in vga_switcheroo_enable()
  * @VGA_SWITCHEROO_IGD: integrated graphics device
  * @VGA_SWITCHEROO_DIS: discrete graphics device
  * @VGA_SWITCHEROO_MAX_CLIENTS: currently no more than two GPUs are supported
@@ -66,6 +69,7 @@ enum vga_switcheroo_state {
  * Client identifier. Audio clients use the same identifier & 0x100.
  */
 enum vga_switcheroo_client_id {
+       VGA_SWITCHEROO_UNKNOWN_ID = -1,
        VGA_SWITCHEROO_IGD,
        VGA_SWITCHEROO_DIS,
        VGA_SWITCHEROO_MAX_CLIENTS,