From 156d7d4120e1c860fde667fc30eeae84bc3e7a25 Mon Sep 17 00:00:00 2001 From: Lukas Wunner Date: Mon, 11 Jan 2016 20:09:20 +0100 Subject: [PATCH] vga_switcheroo: Add handler flags infrastructure Allow handlers to declare their capabilities and allow clients to obtain that information. So far we have these use cases: * If the handler is able to switch DDC separately, clients need to probe EDID with drm_get_edid_switcheroo(). We should allow them to detect a capable handler to ensure this function only gets called when needed. * Likewise if the handler is unable to switch AUX separately, the active client needs to communicate link training parameters to the inactive client, which may then skip the AUX handshake and set up its output with these pre-calibrated values (DisplayPort specification v1.1a, section 2.5.3.3). Clients need a way to recognize such a situation. The flags for the radeon_atpx_handler and amdgpu_atpx_handler are initially set to 0, this can later on be amended with handler_flags |= VGA_SWITCHEROO_CAN_SWITCH_DDC; when a ->switch_ddc callback is added. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88861 Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=61115 Tested-by: Lukas Wunner [MBP 9,1 2012 intel IVB + nvidia GK107 pre-retina 15"] Signed-off-by: Lukas Wunner Reviewed-by: Darren Hart Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/2b0d93ed6e511ca09e95e45e0b35627f330fabce.1452525860.git.lukas@wunner.de --- Documentation/DocBook/gpu.tmpl | 1 + .../gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c | 3 +- drivers/gpu/drm/nouveau/nouveau_acpi.c | 2 +- drivers/gpu/drm/radeon/radeon_atpx_handler.c | 3 +- drivers/gpu/vga/vga_switcheroo.c | 22 ++++++++++++++- drivers/platform/x86/apple-gmux.c | 2 +- include/linux/vga_switcheroo.h | 28 +++++++++++++++++-- 7 files changed, 54 insertions(+), 7 deletions(-) diff --git a/Documentation/DocBook/gpu.tmpl b/Documentation/DocBook/gpu.tmpl index 49c97913c5ae..d6579d8c1341 100644 --- a/Documentation/DocBook/gpu.tmpl +++ b/Documentation/DocBook/gpu.tmpl @@ -3422,6 +3422,7 @@ int num_ioctls; Public constants +!Finclude/linux/vga_switcheroo.h vga_switcheroo_handler_flags_t !Finclude/linux/vga_switcheroo.h vga_switcheroo_client_id !Finclude/linux/vga_switcheroo.h vga_switcheroo_state diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c index 3c895863fcf5..fa948dcbdd5d 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c @@ -552,13 +552,14 @@ static bool amdgpu_atpx_detect(void) void amdgpu_register_atpx_handler(void) { bool r; + enum vga_switcheroo_handler_flags_t handler_flags = 0; /* detect if we have any ATPX + 2 VGA in the system */ r = amdgpu_atpx_detect(); if (!r) return; - vga_switcheroo_register_handler(&amdgpu_atpx_handler); + vga_switcheroo_register_handler(&amdgpu_atpx_handler, handler_flags); } /** diff --git a/drivers/gpu/drm/nouveau/nouveau_acpi.c b/drivers/gpu/drm/nouveau/nouveau_acpi.c index d5e6938cc6bc..cdf522770cfa 100644 --- a/drivers/gpu/drm/nouveau/nouveau_acpi.c +++ b/drivers/gpu/drm/nouveau/nouveau_acpi.c @@ -314,7 +314,7 @@ void nouveau_register_dsm_handler(void) if (!r) return; - vga_switcheroo_register_handler(&nouveau_dsm_handler); + vga_switcheroo_register_handler(&nouveau_dsm_handler, 0); } /* Must be called for Optimus models before the card can be turned off */ diff --git a/drivers/gpu/drm/radeon/radeon_atpx_handler.c b/drivers/gpu/drm/radeon/radeon_atpx_handler.c index c4b4f298a283..56482e35d43e 100644 --- a/drivers/gpu/drm/radeon/radeon_atpx_handler.c +++ b/drivers/gpu/drm/radeon/radeon_atpx_handler.c @@ -551,13 +551,14 @@ static bool radeon_atpx_detect(void) void radeon_register_atpx_handler(void) { bool r; + enum vga_switcheroo_handler_flags_t handler_flags = 0; /* 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); + vga_switcheroo_register_handler(&radeon_atpx_handler, handler_flags); } /** diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c index 665ab9fd0e01..e89f6ad5d83e 100644 --- a/drivers/gpu/vga/vga_switcheroo.c +++ b/drivers/gpu/vga/vga_switcheroo.c @@ -126,6 +126,7 @@ static DEFINE_MUTEX(vgasr_mutex); * (counting only vga clients, not audio clients) * @clients: list of registered clients * @handler: registered handler + * @handler_flags: flags of registered handler * * vga_switcheroo private data. Currently only one vga_switcheroo instance * per system is supported. @@ -142,6 +143,7 @@ struct vgasr_priv { struct list_head clients; const struct vga_switcheroo_handler *handler; + enum vga_switcheroo_handler_flags_t handler_flags; }; #define ID_BIT_AUDIO 0x100 @@ -190,13 +192,15 @@ static void vga_switcheroo_enable(void) /** * vga_switcheroo_register_handler() - register handler * @handler: handler callbacks + * @handler_flags: handler flags * * Register handler. Enable vga_switcheroo if two vga clients have already * registered. * * Return: 0 on success, -EINVAL if a handler was already registered. */ -int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler) +int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler, + enum vga_switcheroo_handler_flags_t handler_flags) { mutex_lock(&vgasr_mutex); if (vgasr_priv.handler) { @@ -205,6 +209,7 @@ int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler } vgasr_priv.handler = handler; + vgasr_priv.handler_flags = handler_flags; if (vga_switcheroo_ready()) { pr_info("enabled\n"); vga_switcheroo_enable(); @@ -222,6 +227,7 @@ EXPORT_SYMBOL(vga_switcheroo_register_handler); void vga_switcheroo_unregister_handler(void) { mutex_lock(&vgasr_mutex); + vgasr_priv.handler_flags = 0; vgasr_priv.handler = NULL; if (vgasr_priv.active) { pr_info("disabled\n"); @@ -232,6 +238,20 @@ void vga_switcheroo_unregister_handler(void) } EXPORT_SYMBOL(vga_switcheroo_unregister_handler); +/** + * vga_switcheroo_handler_flags() - obtain handler flags + * + * Helper for clients to obtain the handler flags bitmask. + * + * Return: Handler flags. A value of 0 means that no handler is registered + * or that the handler has no special capabilities. + */ +enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) +{ + return vgasr_priv.handler_flags; +} +EXPORT_SYMBOL(vga_switcheroo_handler_flags); + static int register_client(struct pci_dev *pdev, const struct vga_switcheroo_client_ops *ops, enum vga_switcheroo_client_id id, bool active, diff --git a/drivers/platform/x86/apple-gmux.c b/drivers/platform/x86/apple-gmux.c index f236250ac106..c401d4936b65 100644 --- a/drivers/platform/x86/apple-gmux.c +++ b/drivers/platform/x86/apple-gmux.c @@ -705,7 +705,7 @@ static int gmux_probe(struct pnp_dev *pnp, const struct pnp_device_id *id) init_completion(&gmux_data->powerchange_done); gmux_enable_interrupts(gmux_data); - if (vga_switcheroo_register_handler(&gmux_handler)) { + if (vga_switcheroo_register_handler(&gmux_handler, 0)) { ret = -ENODEV; goto err_register_handler; } diff --git a/include/linux/vga_switcheroo.h b/include/linux/vga_switcheroo.h index 69e1d4a1f1b3..a745f4f0f729 100644 --- a/include/linux/vga_switcheroo.h +++ b/include/linux/vga_switcheroo.h @@ -35,6 +35,26 @@ struct pci_dev; +/** + * enum vga_switcheroo_handler_flags_t - handler flags bitmask + * @VGA_SWITCHEROO_CAN_SWITCH_DDC: whether the handler is able to switch the + * DDC lines separately. This signals to clients that they should call + * drm_get_edid_switcheroo() to probe the EDID + * @VGA_SWITCHEROO_NEEDS_EDP_CONFIG: whether the handler is unable to switch + * the AUX channel separately. This signals to clients that the active + * GPU needs to train the link and communicate the link parameters to the + * inactive GPU (mediated by vga_switcheroo). The inactive GPU may then + * skip the AUX handshake and set up its output with these pre-calibrated + * values (DisplayPort specification v1.1a, section 2.5.3.3) + * + * Handler flags bitmask. Used by handlers to declare their capabilities upon + * registering with vga_switcheroo. + */ +enum vga_switcheroo_handler_flags_t { + VGA_SWITCHEROO_CAN_SWITCH_DDC = (1 << 0), + VGA_SWITCHEROO_NEEDS_EDP_CONFIG = (1 << 1), +}; + /** * enum vga_switcheroo_state - client power state * @VGA_SWITCHEROO_OFF: off @@ -132,8 +152,10 @@ int vga_switcheroo_register_audio_client(struct pci_dev *pdev, void vga_switcheroo_client_fb_set(struct pci_dev *dev, struct fb_info *info); -int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler); +int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler, + enum vga_switcheroo_handler_flags_t handler_flags); void vga_switcheroo_unregister_handler(void); +enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void); int vga_switcheroo_process_delayed_switch(void); @@ -150,11 +172,13 @@ static inline void vga_switcheroo_unregister_client(struct pci_dev *dev) {} static inline int vga_switcheroo_register_client(struct pci_dev *dev, const struct vga_switcheroo_client_ops *ops, bool driver_power_control) { return 0; } static inline void vga_switcheroo_client_fb_set(struct pci_dev *dev, struct fb_info *info) {} -static inline int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler) { return 0; } +static inline int vga_switcheroo_register_handler(const struct vga_switcheroo_handler *handler, + enum vga_switcheroo_handler_flags_t handler_flags) { return 0; } static inline int vga_switcheroo_register_audio_client(struct pci_dev *pdev, const struct vga_switcheroo_client_ops *ops, enum vga_switcheroo_client_id id) { return 0; } static inline void vga_switcheroo_unregister_handler(void) {} +static inline enum vga_switcheroo_handler_flags_t vga_switcheroo_handler_flags(void) { return 0; } static inline int vga_switcheroo_process_delayed_switch(void) { return 0; } static inline enum vga_switcheroo_state vga_switcheroo_get_client_state(struct pci_dev *dev) { return VGA_SWITCHEROO_ON; }