| Message ID | 20220224224753.297579-1-helgaas@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | vgaarb: Rework default VGA device selection | expand |
On Thu, Feb 24, 2022 at 04:47:42PM -0600, Bjorn Helgaas wrote: > From: Bjorn Helgaas <bhelgaas@google.com> > > Current default VGA device selection fails in some cases because part of it > is done in the vga_arb_device_init() subsys_initcall, and some arches > enumerate PCI devices in pcibios_init(), which runs *after* that. > > The big change from the v8 posting is that this moves vgaarb.c from > drivers/gpu/vga to drivers/pci because it really has nothing to do with > GPUs or DRM. I provisionally applied this to pci/vga and put it into -next just to get a little runtime on it. But I'd prefer not to unilaterally yank this out of drivers/gpu without a consensus from the GPU folks that this is the right thing to do. Any thoughts? If it seems OK to you, I think patch 1/11 (the move itself) is all you would need to look at, although of course I would still be grateful for any review and feedback on the rest. After it's in drivers/pci, all the blame for any issues would come my way. Bjorn
On Fri, Feb 25, 2022 at 04:15:23PM -0600, Bjorn Helgaas wrote: > On Thu, Feb 24, 2022 at 04:47:42PM -0600, Bjorn Helgaas wrote: > > From: Bjorn Helgaas <bhelgaas@google.com> > > > > Current default VGA device selection fails in some cases because part of it > > is done in the vga_arb_device_init() subsys_initcall, and some arches > > enumerate PCI devices in pcibios_init(), which runs *after* that. > > > > The big change from the v8 posting is that this moves vgaarb.c from > > drivers/gpu/vga to drivers/pci because it really has nothing to do with > > GPUs or DRM. > > I provisionally applied this to pci/vga and put it into -next just > to get a little runtime on it. > > But I'd prefer not to unilaterally yank this out of drivers/gpu > without a consensus from the GPU folks that this is the right thing to > do. > > Any thoughts? If it seems OK to you, I think patch 1/11 (the move > itself) is all you would need to look at, although of course I would > still be grateful for any review and feedback on the rest. > > After it's in drivers/pci, all the blame for any issues would come my > way. Ping? This has been in -next since the Feb 28 tree, and I plan to ask Linus to include it during the v5.18 merge window (which will probably open Mar 13) unless somebody objects. Bjorn
I have no objection :) Huacai On Thu, Mar 10, 2022 at 12:29 AM Bjorn Helgaas <helgaas@kernel.org> wrote: > > On Fri, Feb 25, 2022 at 04:15:23PM -0600, Bjorn Helgaas wrote: > > On Thu, Feb 24, 2022 at 04:47:42PM -0600, Bjorn Helgaas wrote: > > > From: Bjorn Helgaas <bhelgaas@google.com> > > > > > > Current default VGA device selection fails in some cases because part of it > > > is done in the vga_arb_device_init() subsys_initcall, and some arches > > > enumerate PCI devices in pcibios_init(), which runs *after* that. > > > > > > The big change from the v8 posting is that this moves vgaarb.c from > > > drivers/gpu/vga to drivers/pci because it really has nothing to do with > > > GPUs or DRM. > > > > I provisionally applied this to pci/vga and put it into -next just > > to get a little runtime on it. > > > > But I'd prefer not to unilaterally yank this out of drivers/gpu > > without a consensus from the GPU folks that this is the right thing to > > do. > > > > Any thoughts? If it seems OK to you, I think patch 1/11 (the move > > itself) is all you would need to look at, although of course I would > > still be grateful for any review and feedback on the rest. > > > > After it's in drivers/pci, all the blame for any issues would come my > > way. > > Ping? This has been in -next since the Feb 28 tree, and I plan to > ask Linus to include it during the v5.18 merge window (which will > probably open Mar 13) unless somebody objects. > > Bjorn
From: Bjorn Helgaas <bhelgaas@google.com> Current default VGA device selection fails in some cases because part of it is done in the vga_arb_device_init() subsys_initcall, and some arches enumerate PCI devices in pcibios_init(), which runs *after* that. The big change from the v8 posting is that this moves vgaarb.c from drivers/gpu/vga to drivers/pci because it really has nothing to do with GPUs or DRM. For example: - On BMC system, the AST2500 bridge [1a03:1150] does not implement PCI_BRIDGE_CTL_VGA. This is perfectly legal but means the legacy VGA resources won't reach downstream devices unless they're included in the usual bridge windows. - vga_arb_select_default_device() will set a device below such a bridge as the default VGA device as long as it has PCI_COMMAND_IO and PCI_COMMAND_MEMORY enabled. - vga_arbiter_add_pci_device() is called for every VGA device, either at boot-time or at hot-add time, and it will also set the device as the default VGA device, but ONLY if all bridges leading to it implement PCI_BRIDGE_CTL_VGA. - This difference between vga_arb_select_default_device() and vga_arbiter_add_pci_device() means that a device below an AST2500 or similar bridge can only be set as the default if it is enumerated before vga_arb_device_init(). - On ACPI-based systems, PCI devices are enumerated by acpi_init(), which runs before vga_arb_device_init(). - On non-ACPI systems, like on MIPS system, they are enumerated by pcibios_init(), which typically runs *after* vga_arb_device_init(). This series consolidates all the default VGA device selection in vga_arbiter_add_pci_device(), which is always called after enumerating a PCI device. Almost all the work here is Huacai's. I restructured it a little bit and added a few trivial patches on top. Bjorn Version history: V0 original implementation as final quirk to set default device. https://lore.kernel.org/r/20210514080025.1828197-6-chenhuacai@loongson.cn V1 rework vgaarb to do all default device selection in vga_arbiter_add_pci_device(). https://lore.kernel.org/r/20210705100503.1120643-1-chenhuacai@loongson.cn V2 move arbiter to PCI subsystem, fix nits. https://lore.kernel.org/r/20210722212920.347118-1-helgaas@kernel.org V3 rewrite the commit log of the last patch (which is also summarized by Bjorn). https://lore.kernel.org/r/20210820100832.663931-1-chenhuacai@loongson.cn V4 split the last patch to two steps. https://lore.kernel.org/r/20210827083129.2781420-1-chenhuacai@loongson.cn V5 split Patch-9 again and sort the patches. https://lore.kernel.org/r/20210911093056.1555274-1-chenhuacai@loongson.cn V6 split Patch-5 again and sort the patches again. https://lore.kernel.org/r/20210916082941.3421838-1-chenhuacai@loongson.cn V7 stop moving vgaarb to drivers/pci because of ordering issues with misc_init(). https://lore.kernel.org/r/20211015061512.2941859-1-chenhuacai@loongson.cn https://lore.kernel.org/r/CAAhV-H7FhAjM-Ha42Z1dLrE4PvC9frfyeU27KHWcyWKkMftEsA@mail.gmail.com V8 expand commit logs, rework boot VGA device selection https://lore.kernel.org/r/20220106000658.243509-1-helgaas@kernel.org V9 (this posting) move to drivers/pci, resolve initcall ordering, rename vga_is_framebuffer_device() to vga_is_firmware_default() Bjorn Helgaas (5): PCI/VGA: Move vgaarb to drivers/pci PCI/VGA: Factor out vga_select_framebuffer_device() PCI/VGA: Remove empty vga_arb_device_card_gone() PCI/VGA: Use unsigned format string to print lock counts PCI/VGA: Replace full MIT license text with SPDX identifier Huacai Chen (6): PCI/VGA: Move vga_arb_integrated_gpu() earlier in file PCI/VGA: Factor out default VGA device selection PCI/VGA: Move firmware default device detection to ADD_DEVICE path PCI/VGA: Move non-legacy VGA detection to ADD_DEVICE path PCI/VGA: Move disabled VGA device detection to ADD_DEVICE path PCI/VGA: Log bridge control messages when adding devices drivers/gpu/vga/Kconfig | 19 -- drivers/gpu/vga/Makefile | 1 - drivers/pci/Kconfig | 19 ++ drivers/pci/Makefile | 1 + drivers/{gpu/vga => pci}/vgaarb.c | 313 +++++++++++++++--------------- 5 files changed, 175 insertions(+), 178 deletions(-) rename drivers/{gpu/vga => pci}/vgaarb.c (90%)