From 485ec8f8e1d8ae12aa1daa5ad345ba8940ad2db7 Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Thu, 6 Apr 2023 15:21:07 +0200 Subject: [PATCH] video/aperture: Only remove sysfb on the default vga pci device [ Upstream commit 5ae3716cfdcd286268133867f67d0803847acefc ] Instead of calling aperture_remove_conflicting_devices() to remove the conflicting devices, just call to aperture_detach_devices() to detach the device that matches the same PCI BAR / aperture range. Since the former is just a wrapper of the latter plus a sysfb_disable() call, and now that's done in this function but only for the primary devices. This fixes a regression introduced by commit ee7a69aa38d8 ("fbdev: Disable sysfb device registration when removing conflicting FBs"), where we remove the sysfb when loading a driver for an unrelated pci device, resulting in the user losing their efifb console or similar. Note that in practice this only is a problem with the nvidia blob, because that's the only gpu driver people might install which does not come with an fbdev driver of it's own. For everyone else the real gpu driver will restore a working console. Also note that in the referenced bug there's confusion that this same bug also happens on amdgpu. But that was just another amdgpu specific regression, which just happened to happen at roughly the same time and with the same user-observable symptoms. That bug is fixed now, see https://bugzilla.kernel.org/show_bug.cgi?id=216331#c15 Note that we should not have any such issues on non-pci multi-gpu issues, because I could only find two such cases: - SoC with some external panel over spi or similar. These panel drivers do not use drm_aperture_remove_conflicting_framebuffers(), so no problem. - vga+mga, which is a direct console driver and entirely bypasses all this. For the above reasons the cc: stable is just notionally, this patch will need a backport and that's up to nvidia if they care enough. v2: - Explain a bit better why other multi-gpu that aren't pci shouldn't have any issues with making all this fully pci specific. v3 - polish commit message (Javier) v4: - Fix commit message style (i.e., commit 1234 ("...")) - fix Daniel's S-o-b address v5: - add back an S-o-b tag with Daniel's Intel address Fixes: ee7a69aa38d8 ("fbdev: Disable sysfb device registration when removing conflicting FBs") Tested-by: Aaron Plattner Reviewed-by: Javier Martinez Canillas Link: https://bugzilla.kernel.org/show_bug.cgi?id=216303#c28 Signed-off-by: Daniel Vetter Signed-off-by: Daniel Vetter Signed-off-by: Thomas Zimmermann Cc: Aaron Plattner Cc: Javier Martinez Canillas Cc: Thomas Zimmermann Cc: Helge Deller Cc: Sam Ravnborg Cc: Alex Deucher Cc: # v5.19+ (if someone else does the backport) Link: https://patchwork.freedesktop.org/patch/msgid/20230406132109.32050-8-tzimmermann@suse.de Signed-off-by: Sasha Levin --- drivers/video/aperture.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/video/aperture.c b/drivers/video/aperture.c index 41e77de1ea82c..5c94abdb1ad6d 100644 --- a/drivers/video/aperture.c +++ b/drivers/video/aperture.c @@ -332,15 +332,16 @@ int aperture_remove_conflicting_pci_devices(struct pci_dev *pdev, const char *na primary = pdev->resource[PCI_ROM_RESOURCE].flags & IORESOURCE_ROM_SHADOW; #endif + if (primary) + sysfb_disable(); + for (bar = 0; bar < PCI_STD_NUM_BARS; ++bar) { if (!(pci_resource_flags(pdev, bar) & IORESOURCE_MEM)) continue; base = pci_resource_start(pdev, bar); size = pci_resource_len(pdev, bar); - ret = aperture_remove_conflicting_devices(base, size, primary, name); - if (ret) - return ret; + aperture_detach_devices(base, size); } /*