kernel/linux.git/drivers/gpu/drm/i915/display/intel_fbdev.c, branch v6.12.102

drm, fbcon, vga_switcheroo: Avoid race condition in fbcon setup

2025-12-06T21:25:03+00:00

[ Upstream commit eb76d0f5553575599561010f24c277cc5b31d003 ] Protect vga_switcheroo_client_fb_set() with console lock. Avoids OOB access in fbcon_remap_all(). Without holding the console lock the call races with switching outputs. VGA switcheroo calls fbcon_remap_all() when switching clients. The fbcon function uses struct fb_info.node, which is set by register_framebuffer(). As the fb-helper code currently sets up VGA switcheroo before registering the framebuffer, the value of node is -1 and therefore not a legal value. For example, fbcon uses the value within set_con2fb_map() [1] as an index into an array. Moving vga_switcheroo_client_fb_set() after register_framebuffer() can result in VGA switching that does not switch fbcon correctly. Therefore move vga_switcheroo_client_fb_set() under fbcon_fb_registered(), which already holds the console lock. Fbdev calls fbcon_fb_registered() from within register_framebuffer(). Serializes the helper with VGA switcheroo's call to fbcon_remap_all(). Although vga_switcheroo_client_fb_set() takes an instance of struct fb_info as parameter, it really only needs the contained fbcon state. Moving the call to fbcon initialization is therefore cleaner than before. Only amdgpu, i915, nouveau and radeon support vga_switcheroo. For all other drivers, this change does nothing. Signed-off-by: Thomas Zimmermann Link: https://elixir.bootlin.com/linux/v6.17/source/drivers/video/fbdev/core/fbcon.c#L2942 # [1] Fixes: 6a9ee8af344e ("vga_switcheroo: initial implementation (v15)") Acked-by: Javier Martinez Canillas Acked-by: Alex Deucher Cc: dri-devel@lists.freedesktop.org Cc: nouveau@lists.freedesktop.org Cc: amd-gfx@lists.freedesktop.org Cc: linux-fbdev@vger.kernel.org Cc: # v2.6.34+ Link: https://patch.msgid.link/20251105161549.98836-1-tzimmermann@suse.de Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

drm/i915: Introduce fb->min_alignment

2024-06-24T14:12:10+00:00

Different planes could have different alignment requirements even for the same format/modifier. Collect the alignment requirements across all planes capable of scanning out the fb such that the alignment is satisfactory to all those planes. So far this was sort of handled by making sure intel_surf_alignment() declares the superset of all planes' alignment requirements, but maintaining that manually is annoying. So we're going to move towards each plane declaring only its own requirements, and thus we need code to generate the superset. v2: Drop the borked per-plane vma optimization (Imre) Assert that the plane's declared alignment is POT (Imre) Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20240612204712.31404-5-ville.syrjala@linux.intel.com Reviewed-by: Imre Deak

drm/i915: Introduce the plane->min_alignment() vfunc

2024-06-24T14:09:50+00:00

Different hardware generations have different scanout alignment requirements. Introduce a new vfunc that will allow us to make that distinction without horrible if-ladders. For now we directly plug in the existing intel_surf_alignment() and intel_cursor_alignment() functions. For fbdev we (temporarily) introduce intel_fbdev_min_alignment() that simply queries the alignment from the primary plane of the first crtc. TODO: someone will need to fix xe's alignment handling Reviewed-by: Imre Deak Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20240612204712.31404-4-ville.syrjala@linux.intel.com Acked-by: Rodrigo Vivi

drm/i915/display: include xe_bo.h, gem_object_types etc. where needed

2024-06-06T13:00:03+00:00

Include what you use. The dependencies on the headers, and what they include, is a bit convoluted. Add xe compat gem/gem_object_types.h. Fix all the places needed. Reviewed-by: Rodrigo Vivi Acked-by: Rodrigo Vivi Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/e9ca3d6127ea22f252d9dbf30cfde99e37538c99.1717004739.git.jani.nikula@intel.com

drm/i915: Rename the fb pinning functions to indicate the address space

2024-05-13T16:23:30+00:00

Rename the fb pinning functions such that their name directly informs us what gets pinned into which address space. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20240506125718.26001-10-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula Acked-by: Lucas De Marchi

drm/i915: Cleanup fbdev fb setup

2024-05-13T16:23:08+00:00

We use a mix of 'intel_fb' vs. 'ifbdev->fb' in the same function. Both should be pointing at the same thing. Make things less confusing by just getting existing fb from 'ifbdev->fb' at the start and then sticking with the local 'fb' (renamed from the 'intel_fb') until the very end. v2: rebase Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20240510102257.25096-1-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula

drm/i915: Change intel_fbdev_fb_alloc() return type

2024-05-13T16:22:48+00:00

Change intel_fbdev_fb_alloc() to return struct intel_fb instead of struct drm_framebuffer. Let's us eliminate some annoying aliasing variables in the fbdev setup code. v2: Assing the results to the correct variable (Jani) Fix xe's copy Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20240510102233.25057-1-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula Acked-by: Lucas De Marchi

drm/{i915, xe}: Implement fbdev emulation as in-kernel client

2024-04-25T11:25:58+00:00

Replace all code that initializes or releases fbdev emulation throughout the driver. Instead initialize the fbdev client by a single call to intel_fbdev_setup() after i915 has registered its DRM device. Just like similar code in other drivers, i915 fbdev emulation now acts like a regular DRM client. Do the same for xe. The fbdev client setup consists of the initial preparation and the hot-plugging of the display. The latter creates the fbdev device and sets up the fbdev framebuffer. The setup performs display hot-plugging once. If no display can be detected, DRM probe helpers re-run the detection on each hotplug event. A call to drm_client_dev_unregister() releases all in-kernel clients automatically. No further action is required within i915. If the fbdev framebuffer has been fully set up, struct fb_ops.fb_destroy implements the release. For partially initialized emulation, the fbdev client reverts the initial setup. Do the same for xe and remove its call to intel_fbdev_fini(). v8: - setup client in intel_display_driver_register (Jouni) - mention xe in commit message v7: - update xe driver - reword commit message v6: - use 'i915' for i915 device (Jouni) - remove unnecessary code for non-atomic mode setting (Jouni, Ville) - fix function name in commit message (Jouni) v3: - as before, silently ignore devices without displays v2: - let drm_client_register() handle initial hotplug - fix driver name in error message (Jani) - fix non-fbdev build (kernel test robot) Signed-off-by: Thomas Zimmermann Reviewed-by: Jouni Högander Acked-by: Lucas De Marchi Link: https://patchwork.freedesktop.org/patch/msgid/20240409081029.17843-7-tzimmermann@suse.de Signed-off-by: Jani Nikula

drm/{i915,xe}: Implement fbdev client callbacks

2024-04-25T11:25:54+00:00

Move code from ad-hoc fbdev callbacks into DRM client functions and remove the old callbacks. The functions instruct the client to poll for changed output or restore the display. The DRM core calls both, the old callbacks and the new client helpers, from the same places. The new functions perform the same operation as before, so there's no change in functionality. Fox xe, remove xe_display_last_close(), which restored the fbdev display. As with i915, the DRM core's drm_lastclose() performs this operation automatically. v8: - mention xe in commit message v7: - update xe driver v6: - return errors from client callbacks (Jouni) Signed-off-by: Thomas Zimmermann Reviewed-by: Jouni Högander Acked-by: Lucas De Marchi Link: https://patchwork.freedesktop.org/patch/msgid/20240409081029.17843-6-tzimmermann@suse.de Signed-off-by: Jani Nikula

drm/i915: Initialize fbdev DRM client with callback functions

2024-04-25T11:25:48+00:00

Initialize i915's fbdev client by giving an instance of struct drm_client_funcs to drm_client_init(). Also clean up with drm_client_release(). Doing this in i915 prevents fbdev helpers from initializing and releasing the client internally (see drm_fb_helper_init()). No functional change yet; the client callbacks will be filled later. v6: - rename client to "intel-fbdev" (Jouni) v2: - call drm_fb_helper_unprepare() in error handling (Jani) - fix typo in commit message (Sam) Signed-off-by: Thomas Zimmermann Reviewed-by: Jouni Högander Acked-by: Lucas De Marchi Link: https://patchwork.freedesktop.org/patch/msgid/20240409081029.17843-4-tzimmermann@suse.de Signed-off-by: Jani Nikula