From: Saurabh Sengar <ssen...@linux.microsoft.com> Sent: Friday, September 9,
2022 7:44 AM
>
> hyperv_setup_vram tries to remove conflicting framebuffer based on
> 'screen_info'. As observed in past due to some bug or wrong setting
> in grub, the 'screen_info' fields may not be set for Gen1, and in such
> cases drm_aperture_remove_conflicting_framebuffers will not do anything
> useful.
> For Gen1 VMs, it should always be possible to get framebuffer
> conflict removed using PCI device instead.
>
> Fixes: a0ab5abced55 ("drm/hyperv : Removing the restruction of VRAM
> allocation with PCI bar size")
> Signed-off-by: Saurabh Sengar <ssen...@linux.microsoft.com>
> ---
> drivers/gpu/drm/hyperv/hyperv_drm_drv.c | 24 ++++++++++++++++++++----
> 1 file changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> index 6d11e7938c83..b0cc974efa45 100644
> --- a/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> +++ b/drivers/gpu/drm/hyperv/hyperv_drm_drv.c
> @@ -73,12 +73,28 @@ static int hyperv_setup_vram(struct hyperv_drm_device *hv,
> struct hv_device *hdev)
> {
> struct drm_device *dev = &hv->dev;
> + struct pci_dev *pdev;
> int ret;
>
> - drm_aperture_remove_conflicting_framebuffers(screen_info.lfb_base,
> - screen_info.lfb_size,
> - false,
> - &hyperv_driver);
> + if (efi_enabled(EFI_BOOT)) {
> +
> drm_aperture_remove_conflicting_framebuffers(screen_info.lfb_base,
> +
> screen_info.lfb_size,
> + false,
> + &hyperv_driver);
> + } else {
> + pdev = pci_get_device(PCI_VENDOR_ID_MICROSOFT,
> PCI_DEVICE_ID_HYPERV_VIDEO, NULL);
> + if (!pdev) {
> + drm_err(dev, "Unable to find PCI Hyper-V video\n");
> + return -ENODEV;
> + }
> +
> + ret = drm_aperture_remove_conflicting_pci_framebuffers(pdev,
> &hyperv_driver);
> + pci_dev_put(pdev);
> + if (ret) {
> + drm_err(dev, "Not able to remove boot fb\n");
> + return ret;
> + }
> + }
>
> hv->fb_size = (unsigned long)hv->mmio_megabytes * 1024 * 1024;
>
> --
> 2.34.1
Reviewed-by: Michael Kelley <mikel...@microsoft.com>
