[PATCH v2 3/7] vga_switcheroo: Add pre_switch callback to client ops
From: Thomas Zimmermann <tzimmermann@suse.de>
Date: 2026-07-09 09:22:39
Also in:
amd-gfx, dri-devel, intel-gfx, nouveau, sashiko-reviews
Subsystem:
drm drivers, drm drivers and misc gpu patches, the rest, vga_switcheroo · Maintainers:
David Airlie, Simona Vetter, Maarten Lankhorst, Maxime Ripard, Thomas Zimmermann, Linus Torvalds
Add pre_switch to struct vga_switcheroo_client_ops to inform the switcheroo client about upcoming switches of the outputs. This callback is intended to replace the hard-coded call to fbdev's fb_switch_outputs(). With DRM supporting more clients than just fbdev emulation, something more flexible is required. v2: - remove non-sensical gpu_bound documentation (Sashiko) Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> --- drivers/gpu/vga/vga_switcheroo.c | 4 +++- include/linux/vga_switcheroo.h | 11 ++++++++--- 2 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/vga/vga_switcheroo.c b/drivers/gpu/vga/vga_switcheroo.c
index 22cf52b78b75..bdf1e56ae891 100644
--- a/drivers/gpu/vga/vga_switcheroo.c
+++ b/drivers/gpu/vga/vga_switcheroo.c@@ -733,8 +733,10 @@ static int vga_switchto_stage2(struct vga_switcheroo_client *new_client) if (!active->driver_power_control) set_audio_state(active->id, VGA_SWITCHEROO_OFF); + if (new_client->ops->pre_switch) + new_client->ops->pre_switch(new_client->pdev); #if defined(CONFIG_FB) - if (new_client->fb_info) + else if (new_client->fb_info) fb_switch_outputs(new_client->fb_info); #endif
diff --git a/include/linux/vga_switcheroo.h b/include/linux/vga_switcheroo.h
index 7e6ac0114d55..4422daca9ceb 100644
--- a/include/linux/vga_switcheroo.h
+++ b/include/linux/vga_switcheroo.h@@ -133,17 +133,22 @@ struct vga_switcheroo_handler { * @can_switch: check if the device is in a position to switch now. * Mandatory. The client should return false if a user space process * has one of its device files open + * @pre_switch: prepare switch + * Optional. This gets called before switching the outputs to the + * GPU. Allows drivers to prepare for the switch. * @gpu_bound: notify the client id to audio client when the GPU is bound. * * Client callbacks. A client can be either a GPU or an audio device on a GPU. - * The @set_gpu_state and @can_switch methods are mandatory, @reprobe may be - * set to NULL. For audio clients, the @reprobe member is bogus. - * OTOH, @gpu_bound is only for audio clients, and not used for GPU clients. + * The @set_gpu_state and @can_switch methods are mandatory, @pre_switch and + * @reprobe may be set to NULL. For audio clients, the @pre_switch and + * @reprobe members are bogus. OTOH, @gpu_bound is only for audio clients, + * and not used for GPU clients. */ struct vga_switcheroo_client_ops { void (*set_gpu_state)(struct pci_dev *dev, enum vga_switcheroo_state); void (*reprobe)(struct pci_dev *dev); bool (*can_switch)(struct pci_dev *dev); + void (*pre_switch)(struct pci_dev *dev); void (*gpu_bound)(struct pci_dev *dev, enum vga_switcheroo_client_id); };
--
2.54.0