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https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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4bdbd5f0ee
A while back we removed it, yet that lead to regressions. At some later point, I've attempted to remove it again without fully grasping the unique (pun intended) situation that virtio is in. Add a bulky comment to document why the call should stay as-is, for the next person who's around. As a Tl;Dr: virtio sits on top of struct virtio_device, which confuses dev_is_pci(), wrong info gets sent to userspace and X doesn't start. Driver needs to explicitly call drm_dev_set_unique() to keep it working. v2: Fix handful of typos (Laszlo) Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: Gerd Hoffmann <kraxel@redhat.com> Cc: Hans de Goede <hdegoede@redhat.com> Cc: Laszlo Ersek <lersek@redhat.com> Signed-off-by: Emil Velikov <emil.velikov@collabora.com> Reviewed-by: Laszlo Ersek <lersek@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20181024144252.16518-1-emil.l.velikov@gmail.com
104 lines
3.3 KiB
C
104 lines
3.3 KiB
C
/*
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* Copyright (C) 2015 Red Hat, Inc.
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* All Rights Reserved.
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*
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* Permission is hereby granted, free of charge, to any person obtaining
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* a copy of this software and associated documentation files (the
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* "Software"), to deal in the Software without restriction, including
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* without limitation the rights to use, copy, modify, merge, publish,
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* distribute, sublicense, and/or sell copies of the Software, and to
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* permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice (including the
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* next paragraph) shall be included in all copies or substantial
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* portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
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* IN NO EVENT SHALL THE COPYRIGHT OWNER(S) AND/OR ITS SUPPLIERS BE
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* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
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* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
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* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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*/
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#include <linux/pci.h>
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#include <drm/drm_fb_helper.h>
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#include "virtgpu_drv.h"
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int drm_virtio_init(struct drm_driver *driver, struct virtio_device *vdev)
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{
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struct drm_device *dev;
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int ret;
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dev = drm_dev_alloc(driver, &vdev->dev);
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if (IS_ERR(dev))
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return PTR_ERR(dev);
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vdev->priv = dev;
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if (strcmp(vdev->dev.parent->bus->name, "pci") == 0) {
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struct pci_dev *pdev = to_pci_dev(vdev->dev.parent);
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const char *pname = dev_name(&pdev->dev);
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bool vga = (pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA;
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char unique[20];
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DRM_INFO("pci: %s detected at %s\n",
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vga ? "virtio-vga" : "virtio-gpu-pci",
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pname);
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dev->pdev = pdev;
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if (vga)
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drm_fb_helper_remove_conflicting_pci_framebuffers(pdev,
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0,
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"virtiodrmfb");
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/*
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* Normally the drm_dev_set_unique() call is done by core DRM.
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* The following comment covers, why virtio cannot rely on it.
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*
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* Unlike the other virtual GPU drivers, virtio abstracts the
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* underlying bus type by using struct virtio_device.
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*
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* Hence the dev_is_pci() check, used in core DRM, will fail
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* and the unique returned will be the virtio_device "virtio0",
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* while a "pci:..." one is required.
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*
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* A few other ideas were considered:
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* - Extend the dev_is_pci() check [in drm_set_busid] to
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* consider virtio.
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* Seems like a bigger hack than what we have already.
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*
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* - Point drm_device::dev to the parent of the virtio_device
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* Semantic changes:
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* * Using the wrong device for i2c, framebuffer_alloc and
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* prime import.
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* Visual changes:
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* * Helpers such as DRM_DEV_ERROR, dev_info, drm_printer,
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* will print the wrong information.
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*
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* We could address the latter issues, by introducing
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* drm_device::bus_dev, ... which would be used solely for this.
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*
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* So for the moment keep things as-is, with a bulky comment
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* for the next person who feels like removing this
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* drm_dev_set_unique() quirk.
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*/
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snprintf(unique, sizeof(unique), "pci:%s", pname);
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ret = drm_dev_set_unique(dev, unique);
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if (ret)
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goto err_free;
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}
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ret = drm_dev_register(dev, 0);
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if (ret)
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goto err_free;
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return 0;
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err_free:
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drm_dev_put(dev);
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return ret;
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}
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